cudf

v22.06.01

🚨 Breaking Changes

• Enable Zstandard decompression only when all nvcomp integrations are enabled (#10944) @vuule
• Rename sliced_child to get_sliced_child. (#10885) @bdice
• Add parameters to control page size in Parquet writer (#10882) @etseidl
• Make cudf::test::expect_columns_equal() to fail when comparing unsanitary lists. (#10880) @nvdbaranec
• Cleanup regex compiler fixed quantifiers source (#10843) @davidwendt
• Refactor cudf::contains, renaming and switching parameters role (#10802) @ttnghia
• Generic serialization of all column types (#10784) @wence-
• Return per-file metadata from readers (#10782) @vuule
• HostColumnVectoreCore#isNull should return true for out-of-range rows (#10779) @gerashegalov
• Update groupby::hash to use new row operators for keys (#10770) @PointKernel
• update mangle_dupe_cols behavior in csv reader to match pandas 1.4.0 behavior (#10749) @karthikeyann
• Rename CUDA_TRY macro to CUDF_CUDA_TRY, rename CHECK_CUDA macro to CUDF_CHECK_CUDA. (#10589) @bdice
• Upgrade cudf to support pandas 1.4.x versions (#10584) @galipremsagar
• Move binop methods from Frame to IndexedFrame and standardize the docstring (#10576) @vyasr
• Add default= kwarg to .list.get() accessor method (#10547) @shwina
• Remove deprecated decimal_cols_as_float in the ORC reader (#10515) @vuule
• Support nvComp 2.3 if local, otherwise use nvcomp 2.2 (#10513) @robertmaynard
• Fix findall_record to return empty list for no matches (#10491) @davidwendt
• Namespace/Docstring Fixes for Reduction (#10471) @isVoid
• Additional refactoring of hash functions (#10462) @bdice
• Fix default value of str.split expand parameter. (#10457) @bdice
• Remove deprecated code. (#10450) @vyasr

🐛 Bug Fixes

• Fix single column MultiIndex issue in sort_index (#10957) @galipremsagar
• Make SerializedTableHeader(numRows) public (#10949) @gerashegalov
• Fix gcc_linux version pinning in dev environment (#10943) @galipremsagar
• Fix an issue with reading raw string in cudf.read_json (#10924) @galipremsagar
• Make cudf::test::expect_columns_equal() to fail when comparing unsanitary lists. (#10880) @nvdbaranec
• Fix segmented_reduce on empty column with non-empty offsets (#10876) @davidwendt
• Fix dask-cudf groupby handling when grouping by all columns (#10866) @charlesbluca
• Fix a bug in distinct: using nested nulls logic (#10848) @PointKernel
• Fix constness / references in weak ordering operator() signatures. (#10846) @bdice
• Suppress sizeof-array-div warnings in thrust found by gcc-11 (#10840) @robertmaynard
• Add handling for string by-columns in dask-cudf groupby (#10830) @charlesbluca
• Fix compile warning in search.cu (#10827) @davidwendt
• Fix element access const correctness in hostdevice_vector (#10804) @vuule
• Update cuco git tag (#10788) @PointKernel
• HostColumnVectoreCore#isNull should return true for out-of-range rows (#10779) @gerashegalov
• Fixing deprecation warnings in test_orc.py (#10772) @hyperbolic2346
• Enable writing to s3 storage in chunked parquet writer (#10769) @galipremsagar
• Fix construction of nested structs with EMPTY child (#10761) @shwina
• Fix replace error when regex has only zero match quantifiers (#10760) @davidwendt
• Fix an issue with one_level_list schemas in parquet reader. (#10750) @nvdbaranec
• update mangle_dupe_cols behavior in csv reader to match pandas 1.4.0 behavior (#10749) @karthikeyann
• Fix cupy function in notebook (#10737) @ajschmidt8
• Fix fillna to retain columns when it is MultiIndex (#10729) @galipremsagar
• Fix scatter for all-empty-string column case (#10724) @davidwendt
• Retain series name in Series.apply (#10716) @brandon-b-miller
• Correct build dir cudf-config dependency issues for static builds (#10704) @robertmaynard
• Fix list of testing requirements in setup.py. (#10678) @bdice
• Fix rounding to zero error in stod on very small float numbers (#10672) @davidwendt
• cuco isn't a cudf dependency when we are built shared (#10662) @robertmaynard
• Fix to_timestamps to support Z for %z format specifier (#10617) @davidwendt
• Verify compression type in Parquet reader (#10610) @vuule
• Fix struct row comparator's exception on empty structs (#10604) @sperlingxx
• Fix strings strip() to accept only str Scalar for to_strip parameter (#10597) @davidwendt
• Fix has_atomic_support check in can_use_hash_groupby() (#10588) @jbrennan333
• Revert Thrust 1.16 to Thrust 1.15 (#10586) @bdice
• Fix missing RMM_STATIC_CUDART define when compiling JNI with static CUDA runtime (#10585) @jlowe
• pin more cmake versions (#10570) @robertmaynard
• Re-enable Build Metrics Report (#10562) @davidwendt
• Remove statically linked CUDA runtime check in Java build (#10532) @jlowe
• Fix temp data cleanup in test_text.py (#10524) @brandon-b-miller
• Update pre-commit to run black 22.3.0 (#10523) @vyasr
• Remove deprecated decimal_cols_as_float in the ORC reader (#10515) @vuule
• Fix findall_record to return empty list for no matches (#10491) @davidwendt
• Allow users to specify data types for a subset of columns in read_csv (#10484) @vuule
• Fix default value of str.split expand parameter. (#10457) @bdice
• Improve coverage of dask-cudf's groupby aggregation, add tests for dropna support (#10449) @charlesbluca
• Allow string aggs for dask_cudf.CudfDataFrameGroupBy.aggregate (#10222) @charlesbluca
• In-place updates with loc or iloc don't work correctly when the LHS has more than one column (#9918) @skirui-source

📖 Documentation

• Clarify append deprecation notice. (#10930) @bdice
• Use full name of GPUDirect Storage SDK in docs (#10904) @vuule
• Update Dask + Pandas to Dask + cuDF path (#10897) @miguelusque
• Add missing documentation in cudf/types.hpp (#10895) @karthikeyann
• Add strong index iterator docs. (#10888) @bdice
• spell check fixes (#10865) @karthikeyann
• Add missing documentation in scalar/ headers (#10861) @karthikeyann
• Remove typo in ngram documentation (#10859) @miguelusque
• fix doxygen warnings (#10842) @karthikeyann
• Add a library_design.md file documenting the core Python data structures and their relationship (#10817) @vyasr
• Add NumPy to intersphinx references. (#10809) @bdice
• Add a section to the docs that compares cuDF with Pandas (#10796) @shwina
• Mention 2 cpp-reviewer requirement in pull request template (#10768) @davidwendt
• Enable pydocstyle for all packages. (#10759) @bdice
• Enable pydocstyle rules involving quotes (#10748) @vyasr
• Revise 10 minutes notebook. (#10738) @bdice
• Reorganize cuDF Python docs (#10691) @shwina
• Fix sphinx/jupyter heading issue in UDF notebook (#10690) @brandon-b-miller
• Migrated user guide notebooks to MyST-NB and added sphinx extension (#10685) @mmccarty
• add data generation to benchmark documentation (#10677) @karthikeyann
• Fix some docs build warnings (#10674) @galipremsagar
• Update UDF notebook in User Guide. (#10668) @bdice
• Improve User Guide docs (#10663) @bdice
• Fix some docstrings formatting (#10660) @galipremsagar
• Remove implementation details from apply docstrings (#10651) @brandon-b-miller
• Revise CONTRIBUTING.md (#10644) @bdice
• Add missing APIs to documentation. (#10643) @bdice
• Use cudf.read_json as documented API name. (#10640) @bdice
• Fix docstring section headings. (#10639) @bdice
• Document cudf.read_text and cudf.read_avro. (#10638) @bdice
• Fix type-o in docstring for json_reader_options (#10627) @dagardner-nv
• Update guide to UDFs with notes about Series.applymap deprecation and related changes (#10607) @brandon-b-miller
• Fix doxygen Modules page for cudf::lists::sequences (#10561) @davidwendt
• Add Replace Backreferences section to Regex Features page (#10560) @davidwendt
• Introduce deprecation policy to developer guide. (#10252) @vyasr

🚀 New Features

• Enable Zstandard decompression only when all nvcomp integrations are enabled (#10944) @vuule
• Handle nested types in cudf::concatenate_rows() (#10890) @nvdbaranec
• Strong index types for equality comparator (#10883) @ttnghia
• Add parameters to control page size in Parquet writer (#10882) @etseidl
• Support for Zstandard decompression in ORC reader (#10873) @vuule
• Use pre-built nvcomp 2.3 binaries by default (#10851) @robertmaynard
• Support for Zstandard decompression in Parquet reader (#10847) @vuule
• Add JNI support for apply_boolean_mask (#10812) @res-life
• Segmented Min/Max for Fixed Point Types (#10794) @isVoid
• Return per-file metadata from readers (#10782) @vuule
• Segmented apply_boolean_mask for LIST columns (#10773) @mythrocks
• Update groupby::hash to use new row operators for keys (#10770) @PointKernel
• Support purging non-empty null elements from LIST/STRING columns (#10701) @mythrocks
• Add detail::hash_join (#10695) @PointKernel
• Persist string statistics data across multiple calls to orc chunked write (#10694) @hyperbolic2346
• Add .list.astype() to cast list leaves to specified dtype (#10693) @shwina
• JNI: Add generateListOffsets API (#10683) @sperlingxx
• Support args in groupby apply (#10682) @brandon-b-miller
• Enable segmented_gather in Java package (#10669) @sperlingxx
• Add row hasher with nested column support (#10641) @devavret
• Add support for numeric_only in DataFrame._reduce (#10629) @martinfalisse
• First step toward statistics in ORC files with chunked writes (#10567) @hyperbolic2346
• Add support for struct columns to the random table generator (#10566) @vuule
• Enable passing a sequence for the index argument to .list.get() (#10564) @shwina
• Add python bindings for cudf::list::index_of (#10549) @ChrisJar
• Add default= kwarg to .list.get() accessor method (#10547) @shwina
• Add cudf.DataFrame.applymap (#10542) @brandon-b-miller
• Support nvComp 2.3 if local, otherwise use nvcomp 2.2 (#10513) @robertmaynard
• Add column field ID control in parquet writer (#10504) @PointKernel
• Deprecate Series.applymap (#10497) @brandon-b-miller
• Add option to drop cache in cuIO benchmarks (#10488) @vuule
• move benchmark input generation in device in reduction nvbench (#10486) @karthikeyann
• Support Segmented Min/Max Reduction on String Type (#10447) @isVoid
• List element Equality comparator (#10289) @devavret
• Implement all methods of groupby rank aggregation in libcudf, python (#9569) @karthikeyann
• Implement DataFrame.eval using libcudf ASTs (#8022) @vyasr

🛠️ Improvements

• Use conda compilers in env file (#10915) @galipremsagar
• Remove C style artifacts in cuIO (#10886) @vuule
• Rename sliced_child to get_sliced_child. (#10885) @bdice
• Replace defaulted stream value for libcudf APIs that use NVCOMP (#10877) @jbrennan333
• Add more unit tests for cudf::distinct for nested types with sliced input (#10860) @ttnghia
• Changing list_view.cuh to list_view.hpp (#10854) @ttnghia
• More error checking in from_dlpack (#10850) @wence-
• Cleanup regex compiler fixed quantifiers source (#10843) @davidwendt
• Adds the JNI call for Cuda.deviceSynchronize (#10839) @abellina
• Add missing cuda-python dependency to cudf (#10833) @bdice
• Change std::string parameters in cudf::strings APIs to std::string_view (#10832) @davidwendt
• Split up search.cu to improve compile time (#10831) @davidwendt
• Add tests for null scalar binaryops (#10828) @brandon-b-miller
• Cleanup regex compile optimize functions (#10825) @davidwendt
• Use ThreadedMotoServer instead of subprocess in spinning up s3 server (#10822) @galipremsagar
• Import NA from missing rather than using cudf.NA everywhere (#10821) @brandon-b-miller
• Refactor regex builtin character-class identifiers (#10814) @davidwendt
• Change pattern parameter for regex APIs from std::string to std::string_view (#10810) @davidwendt
• Make the JNI API to get list offsets as a view public. (#10807) @revans2
• Add cudf JNI docker build github action (#10806) @pxLi
• Removed mr parameter from inplace bitmask operations (#10805) @AtlantaPepsi
• Refactor cudf::contains, renaming and switching parameters role (#10802) @ttnghia
• Handle closed property in IntervalDtype.from_pandas (#10798) @wence-
• Return weak orderings from device_row_comparator. (#10793) @rwlee
• Rework Scalar imports (#10791) @brandon-b-miller
• Enable ccache for cudfjni build in Docker (#10790) @gerashegalov
• Generic serialization of all column types (#10784) @wence-
• simplifying skiprows test in test_orc.py (#10783) @hyperbolic2346
• Use column_views instead of column_device_views in binary operations. (#10780) @bdice
• Add struct utility functions. (#10776) @bdice
• Add multiple rows to subword tokenizer benchmark (#10767) @davidwendt
• Refactor host decompression in ORC reader (#10764) @vuule
• Flush output streams before creating a process to drop caches (#10762) @vuule
• Refactor binaryop/compiled/util.cpp (#10756) @bdice
• Use warp per string for long strings in cudf::strings::contains() (#10739) @davidwendt
• Use generator expressions in any/all functions. (#10736) @bdice
• Use canonical "magic methods" (replace x.__repr__() with repr(x)). (#10735) @bdice
• Improve use of isinstance. (#10734) @bdice
• Rename tests from multiIndex to multiindex. (#10732) @bdice
• Two-table comparators with strong index types (#10730) @bdice
• Replace std::make_pair with std::pair (C++17 CTAD) (#10727) @karthikeyann
• Use structured bindings instead of std::tie (#10726) @karthikeyann
• Missing f prefix on f-strings fix (#10721) @code-review-doctor
• Add max_file_size parameter to chunked parquet dataset writer (#10718) @galipremsagar
• Deprecate merge_sorted, change dask cudf usage to internal method (#10713) @isVoid
• Prepare dask_cudf test_parquet.py for upcoming API changes (#10709) @rjzamora
• Remove or simplify various utility functions (#10705) @vyasr
• Allow building arrow with parquet and not python (#10702) @revans2
• Partial cuIO GPU decompression refactor (#10699) @vuule
• Cython API refactor: merge.pyx (#10698) @isVoid
• Fix random string data length to become variable (#10697) @galipremsagar
• Add bindings for index_of with column search key (#10696) @ChrisJar
• Deprecate index merging (#10689) @vyasr
• Remove cudf::strings::string namespace (#10684) @davidwendt
• Standardize imports. (#10680) @bdice
• Standardize usage of collections.abc. (#10679) @bdice
• Cython API Refactor: transpose.pyx, sort.pyx (#10675) @isVoid
• Add device_memory_resource parameter to create_string_vector_from_column (#10673) @davidwendt
• Split up mixed-join kernels source files (#10671) @davidwendt
• Use std::filesystem for temporary directory location and deletion (#10664) @vuule
• cleanup benchmark includes (#10661) @karthikeyann
• Use upstream clang-format pre-commit hook. (#10659) @bdice
• Clean up C++ includes to use <> instead of "". (#10658) @bdice
• Handle RuntimeError thrown by CUDA Python in validate_setup (#10653) @shwina
• Rework JNI CMake to leverage rapids_find_package (#10649) @jlowe
• Use conda to build python packages during GPU tests (#10648) @Ethyling
• Deprecate various functions that don't need to be defined for Index. (#10647) @vyasr
• Update pinning to allow newer CMake versions. (#10646) @vyasr
• Bump hadoop-common from 3.1.4 to 3.2.3 in /java (#10645) @dependabot[bot]
• Remove concurrent_unordered_multimap. (#10642) @bdice
• Improve parquet dictionary encoding (#10635) @PointKernel
• Improve cudf::cuda_error (#10630) @sperlingxx
• Add support for null and non-numeric types in Series.diff and DataFrame.diff (#10625) @Matt711
• Branch 22.06 merge 22.04 (#10624) @vyasr
• Unpin dask & distributed for development (#10623) @galipremsagar
• Slightly improve accuracy of stod in to_floats (#10622) @davidwendt
• Allow libcudfjni to be built as a static library (#10619) @jlowe
• Change stack-based regex state data to use global memory (#10600) @davidwendt
• Resolve Forward merging of branch-22.04 into branch-22.06 (#10598) @galipremsagar
• KvikIO as an alternative GDS backend (#10593) @madsbk
• Rename CUDA_TRY macro to CUDF_CUDA_TRY, rename CHECK_CUDA macro to CUDF_CHECK_CUDA. (#10589) @bdice
• Upgrade cudf to support pandas 1.4.x versions (#10584) @galipremsagar
• Refactor binary ops for timedelta and datetime columns (#10581) @vyasr
• Refactor cudf::strings::count_re API to use count_matches utility (#10580) @davidwendt
• Update Programming Language :: Python Versions to 3.8 & 3.9 (#10579) @madsbk
• Automate Java cudf jar build with statically linked dependencies (#10578) @gerashegalov
• Add patch for thrust-cub 1.16 to fix sort compile times (#10577) @davidwendt
• Move binop methods from Frame to IndexedFrame and standardize the docstring (#10576) @vyasr
• Cleanup libcudf strings regex classes (#10573) @davidwendt
• Simplify preprocessing of arguments for DataFrame binops (#10563) @vyasr
• Reduce kernel calls to build strings findall results (#10559) @davidwendt
• Forward-merge branch-22.04 to branch-22.06 (#10557) @bdice
• Update strings contains benchmark to measure varying match rates (#10555) @davidwendt
• JNI: throw CUDA errors more specifically (#10551) @sperlingxx
• Enable building static libs (#10545) @trxcllnt
• Remove pip requirements files. (#10543) @bdice
• Remove Click pinnings that are unnecessary after upgrading black. (#10541) @vyasr
• Refactor memory_usage to improve performance (#10537) @galipremsagar
• Adjust the valid range of group index for replace_with_backrefs (#10530) @sperlingxx
• add accidentally removed comment. (#10526) @vyasr
• Update conda environment. (#10525) @vyasr
• Remove ColumnBase.getitem (#10516) @vyasr
• Optimize left_semi_join by materializing the gather mask (#10511) @cheinger
• Define proper binary operation APIs for columns (#10509) @vyasr
• Upgrade arrow-cpp & pyarrow to 7.0.0 (#10503) @galipremsagar
• Update to Thrust 1.16 (#10489) @bdice
• Namespace/Docstring Fixes for Reduction (#10471) @isVoid
• Update cudfjni 22.06.0-SNAPSHOT (#10467) @pxLi
• Use Lists of Columns for Various Files (#10463) @isVoid
• Additional refactoring of hash functions (#10462) @bdice
• Fix Series.str.findall behavior for expand=False. (#10459) @bdice
• Remove deprecated code. (#10450) @vyasr
• Update cmake-format version. (#10440) @vyasr
• Consolidate C++ conda recipes and add libcudf-tests package (#10326) @ajschmidt8
• Use conda compilers (#10275) @Ethyling
• Add row bitmask as a detail::hash_join member (#10248) @PointKernel

🚨 Breaking Changes

• Drop unsupported method argument from nunique and distinct_count. (#10411) @bdice
• Refactor stream compaction APIs (#10370) @PointKernel
• Add scan_aggregation and reduce_aggregation derived types. (#10357) @nvdbaranec
• Avoid decimal type narrowing for decimal binops (#10299) @galipremsagar
• Rewrites sample API (#10262) @isVoid
• Remove probe-time null equality parameters in cudf::hash_join (#10260) @PointKernel
• Enable proper Index round-tripping in orc reader and writer (#10170) @galipremsagar
• Add JNI for strings::split_re and strings::split_record_re (#10139) @ttnghia
• Change cudf::strings::find_multiple to return a lists column (#10134) @davidwendt
• Remove the option to completely disable decimal128 columns in the ORC reader (#10127) @vuule
• Remove deprecated code (#10124) @vyasr
• Update gpu_utils.py to reflect current CUDA support. (#10113) @bdice
• Optimize compaction operations (#10030) @PointKernel
• Remove deprecated method Series.set_index. (#9945) @bdice
• Add cudf::strings::findall_record API (#9911) @davidwendt
• Upgrade arrow & pyarrow to 6.0.1 (#9686) @galipremsagar

🐛 Bug Fixes

• Fix an issue with tdigest merge aggregations. (#10506) @nvdbaranec
• Batch of fixes for index overflows in grid stride loops. (#10448) @nvdbaranec
• Update dask_cudf imports to be compatible with latest dask (#10442) @rlratzel
• Fix for integer overflow in contiguous-split (#10437) @jbrennan333
• Fix has_null predicate for drop_list_duplicates on nested structs (#10436) @sperlingxx
• Fix empty reduce with List output and non-List input (#10435) @sperlingxx
• Fix list and struct meta generation issue in dask-cudf (#10434) @galipremsagar
• Fix error in cudf.to_numeric when a bool input is passed (#10431) @galipremsagar
• Support cupy array in quantile input (#10429) @galipremsagar
• Fix benchmarks to work with new aggregation types (#10428) @davidwendt
• Fix cudf::shift to handle offset greater than column size (#10414) @davidwendt
• Fix lifespan of the temporary directory that holds cuFile configuration file (#10403) @vuule
• Fix error thrown in compiled-binaryop benchmark (#10398) @davidwendt
• Limiting async allocator using alignment of 512 (#10395) @rongou
• Include <optional> in multibyte split. (#10385) @bdice
• Fix issue with column and scalar re-assignment (#10377) @galipremsagar
• Fix floating point data generation in benchmarks (#10372) @vuule
• Avoid overflow in fused_concatenate_kernel output_index (#10344) @abellina
• Remove is_relationally_comparable for table device views (#10342) @davidwendt
• Fix debug compile error in device_span to column_view conversion (#10331) @davidwendt
• Add Pascal support to JCUDF transcode (row_conversion) (#10329) @mythrocks
• Fix std::bad_alloc exception due to JIT reserving a huge buffer (#10317) @ttnghia
• Fixes up the overflowed fixed-point round on nullable column (#10316) @sperlingxx
• Fix DataFrame slicing issues for empty cases (#10310) @brandon-b-miller
• Fix documentation issues (#10307) @ajschmidt8
• Allow Java bindings to use default decimal precisions when writing columns (#10276) @sperlingxx
• Fix incorrect slicing of GDS read/write calls (#10274) @vuule
• Fix out-of-memory error in compiled-binaryop benchmark (#10269) @davidwendt
• Add tests of reflected ufuncs and fix behavior of logical reflected ufuncs (#10261) @vyasr
• Remove probe-time null equality parameters in cudf::hash_join (#10260) @PointKernel
• Fix out-of-memory error in UrlDecode benchmark (#10258) @davidwendt
• Fix groupby reductions that perform operations on source type instead of target type (#10250) @ttnghia
• Fix small leak in explode (#10245) @revans2
• Yet another small JNI memory leak (#10238) @revans2
• Fix regex octal parsing to limit to 3 characters (#10233) @davidwendt
• Fix string to decimal128 conversion handling large exponents (#10231) @davidwendt
• Fix JNI leak on copy to device (#10229) @revans2
• Fix the data generator element size for decimal types (#10225) @vuule
• Fix decimal metadata in parquet writer (#10224) @galipremsagar
• Fix strings handling of hex in regex pattern (#10220) @davidwendt
• Fix docs builds (#10216) @ajschmidt8
• Fix a leftover _has_nulls change from Nullate (#10211) @devavret
• Fix bitmask of the output for JNI of lists::drop_list_duplicates (#10210) @ttnghia
• Fix compile error in binaryop/compiled/util.cpp (#10209) @ttnghia
• Skip ORC and Parquet readers' benchmark cases that are not currently supported (#10194) @vuule
• Fix JNI leak of a cudf::column_view native class. (#10171) @revans2
• Enable proper Index round-tripping in orc reader and writer (#10170) @galipremsagar
• Convert Column Name to String Before Using Struct Column Factory (#10156) @isVoid
• Preserve the correct ListDtype while creating an identical empty column (#10151) @galipremsagar
• benchmark fixture - static object pointer fix (#10145) @karthikeyann
• Fix UDF Caching (#10133) @brandon-b-miller
• Raise duplicate column error in DataFrame.rename (#10120) @galipremsagar
• Fix flaky memory usage test by guaranteeing array size. (#10114) @vyasr
• Encode values from python callback for C++ (#10103) @jdye64
• Add check for regex instructions causing an infinite-loop (#10095) @davidwendt
• Remove metadata singleton from nvtext normalizer (#10090) @davidwendt
• Column equality testing fixes (#10011) @brandon-b-miller
• Pin libcudf runtime dependency for cudf / libcudf-kafka nightlies (#9847) @charlesbluca

📖 Documentation

• Fix documentation for DataFrame.corr and Series.corr. (#10493) @bdice
• Add cut to API docs (#10479) @shwina
• Remove documentation for methods removed in #10124. (#10366) @bdice
• Fix documentation issues (#10306) @ajschmidt8
• Fix fixed_point binary operation documentation (#10198) @codereport
• Remove cleaned up methods from docs (#10189) @galipremsagar
• Update developer guide to recommend no default stream parameter. (#10136) @bdice
• Update benchmarking guide to use NVBench. (#10093) @bdice

🚀 New Features

• Add StringIO support to read_text (#10465) @cwharris
• Add support for tdigest and merge_tdigest aggregations through cudf::reduce (#10433) @nvdbaranec
• JNI support for Collect Ops in Reduction (#10427) @sperlingxx
• Enable read_text with dask_cudf using byte_range (#10407) @ChrisJar
• Add cudf::stable_sort_by_key (#10387) @PointKernel
• Implement maps_column_view abstraction over LIST<STRUCT<K,V>> (#10380) @mythrocks
• Support Java bindings for Avro reader (#10373) @HaoYang670
• Refactor stream compaction APIs (#10370) @PointKernel
• Support collect aggregations in reduction (#10353) @sperlingxx
• Refactor array_ufunc for Index and unify across all classes (#10346) @vyasr
• Add JNI for extract_list_element with index column (#10341) @firestarman
• Support min and max operations for structs in rolling window (#10332) @ttnghia
• Add device create_sequence_table for benchmarks (#10300) @karthikeyann
• Enable numpy ufuncs for DataFrame (#10287) @vyasr
• move input generation for json benchmark to device (#10281) @karthikeyann
• move input generation for type dispatcher benchmark to device (#10280) @karthikeyann
• move input generation for copy benchmark to device (#10279) @karthikeyann
• generate url decode benchmark input in device (#10278) @karthikeyann
• device input generation in join bench (#10277) @karthikeyann
• Add nvtext::byte_pair_encoding API (#10270) @davidwendt
• Prevent internal usage of expensive APIs (#10263) @vyasr
• Column to JCUDF row for tables with strings (#10235) @hyperbolic2346
• Support percent_rank() aggregation (#10227) @mythrocks
• Refactor Series.array_ufunc (#10217) @vyasr
• Reduce pytest runtime (#10203) @brandon-b-miller
• Add regex flags parameter to python cudf strings split (#10185) @davidwendt
• Support for MOD, PMOD and PYMOD for decimal32/64/128 (#10179) @codereport
• Adding string row size iterator for row to column and column to row conversion (#10157) @hyperbolic2346
• Add file size counter to cuIO benchmarks (#10154) @vuule
• byte_range support for multibyte_split/read_text (#10150) @cwharris
• Add JNI for strings::split_re and strings::split_record_re (#10139) @ttnghia
• Add maxSplit parameter to Java binding for strings:split (#10137) @ttnghia
• Add libcudf strings split API that accepts regex pattern (#10128) @davidwendt
• generate benchmark input in device (#10109) @karthikeyann
• Avoid nan_as_null op if nan_count is 0 (#10082) @galipremsagar
• Add Dataframe and Index nunique (#10077) @martinfalisse
• Support nanosecond timestamps in parquet (#10063) @PointKernel
• Java bindings for mixed semi and anti joins (#10040) @jlowe
• Implement mixed equality/conditional semi/anti joins (#10037) @vyasr
• Optimize compaction operations (#10030) @PointKernel
• Support args= in Series.apply (#9982) @brandon-b-miller
• Add cudf::strings::findall_record API (#9911) @davidwendt
• Add covariance for sort groupby (python) (#9889) @mayankanand007
• Implement DataFrame diff() (#9817) @skirui-source
• Implement DataFrame pct_change (#9805) @skirui-source
• Support segmented reductions and null mask reductions (#9621) @isVoid
• Add 'spearman' correlation method for dataframe.corr and series.corr (#7141) @dominicshanshan

🛠️ Improvements

• Add scipy skip for a test (#10502) @galipremsagar
• Temporarily disable new ops-bot functionality (#10496) @ajschmidt8
• Include <cstddef> to fix compilation of parquet reader on GCC 11. (#10483) @bdice
• Pin dask and distributed (#10481) @galipremsagar
• MD5 refactoring. (#10445) @bdice
• Remove or split up Frame methods that use the index (#10439) @vyasr
• Centralization of tdigest aggregation code. (#10422) @nvdbaranec
• Simplify column binary operations (#10421) @vyasr
• Add .github/ops-bot.yaml config file (#10420) @ajschmidt8
• Use list of columns for methods in Groupby.pyx (#10419) @isVoid
• Remove warnings in test_timedelta.py (#10418) @galipremsagar
• Fix some warnings in test_parquet.py (#10416) @galipremsagar
• JNI support for segmented reduce (#10413) @revans2
• Clean up null mask after purging null entries (#10412) @sperlingxx
• Drop unsupported method argument from nunique and distinct_count. (#10411) @bdice
• Use str instead of builtins.str. (#10410) @bdice
• Fix warnings in test_rolling (#10405) @bdice
• Enable codecov github-check in CI (#10404) @galipremsagar
• Fix warnings in test_cuda_apply, test_numerical, test_pickling, test_unaops. (#10402) @bdice
• Set column names in _from_columns_like_self factory (#10400) @isVoid
• Refactor nvtx annotations in cudf & dask-cudf (#10396) @galipremsagar
• Consolidate .cov and .corr for sort groupby (#10386) @skirui-source
• Consolidate some Frame APIs (#10381) @vyasr
• Refactor hash functions and hash_combine (#10379) @bdice
• Add nvtx annotations for Series and Index (#10374) @galipremsagar
• Refactor filling.repeat API (#10371) @isVoid
• Move standalone UTF8 functions from string_view.hpp to utf8.hpp (#10369) @davidwendt
• Remove doc for deprecated function one_hot_encoding (#10367) @isVoid
• Refactor array function (#10364) @vyasr
• Fix warnings in test_csv.py. (#10362) @bdice
• Implement a mixin for binops (#10360) @vyasr
• Refactor cython interface: copying.pyx (#10359) @isVoid
• Implement a mixin for scans (#10358) @vyasr
• Add scan_aggregation and reduce_aggregation derived types. (#10357) @nvdbaranec
• Add cleanup of python artifacts (#10355) @galipremsagar
• Fix warnings in test_categorical.py. (#10354) @bdice
• Create a dispatcher for invoking regex kernel functions (#10349) @davidwendt
• Fix codecov in CI (#10347) @galipremsagar
• Enable caching for memory_usage calculation in Column (#10345) @galipremsagar
• C++17 cleanup: traits replace std::enable_if<>::type with std::enable_if_t (#10343) @karthikeyann
• JNI: Support appending DECIMAL128 into ColumnBuilder in terms of byte array (#10338) @sperlingxx
• multibyte_split test improvements (#10328) @vuule
• Fix warnings in test_binops.py. (#10327) @bdice
• Fix warnings from pandas in test_array_ufunc.py. (#10324) @bdice
• Update upload script (#10321) @ajschmidt8
• Move hash type declarations to hashing.hpp (#10320) @davidwendt
• C++17 cleanup: traits replace ::value with _v (#10319) @karthikeyann
• Remove internal columns usage (#10315) @vyasr
• Remove extraneous build.sh parameter (#10313) @ajschmidt8
• Add const qualifier to MurmurHash3_32::hash_combine (#10311) @davidwendt
• Remove TODO in libcudf_kafka recipe (#10309) @ajschmidt8
• Add conversions between column_view and device_span<T const>. (#10302) @bdice
• Avoid decimal type narrowing for decimal binops (#10299) @galipremsagar
• Deprecate DataFrame.iteritems and introduce .items (#10298) @galipremsagar
• Explicitly request CMake use gnu++17 over c++17 (#10297) @robertmaynard
• Add copyright check as pre-commit hook. (#10290) @vyasr
• DataFrame insert and creation optimizations (#10285) @galipremsagar
• Improve hash join detail functions (#10273) @PointKernel
• Replace custom cached_property implementation with functools (#10272) @shwina
• Rewrites sample API (#10262) @isVoid
• Bump hadoop-common from 3.1.0 to 3.1.4 in /java (#10259) @dependabot[bot]
• Remove making redundant copy across code-base (#10257) @galipremsagar
• Add more nvtx annotations (#10256) @galipremsagar
• Add copyright check in cudf (#10253) @galipremsagar
• Remove redundant copies in fillna to improve performance (#10241) @galipremsagar
• Remove std::numeric_limit specializations for timestamp & durations (#10239) @codereport
• Optimize DataFrame creation across code-base (#10236) @galipremsagar
• Change pytest distribution algorithm and increase parallelism in CI (#10232) @galipremsagar
• Add environment variables for I/O thread pool and slice sizes (#10218) @vuule
• Add regex flags to strings findall functions (#10208) @davidwendt
• Update dask-cudf parquet tests to reflect upstream bugfixes to _metadata (#10206) @charlesbluca
• Remove unnecessary nunique function in Series. (#10205) @martinfalisse
• Refactor DataFrame tests. (#10204) @bdice
• Rewrites column.__setitem__, Use boolean_mask_scatter (#10202) @isVoid
• Java utilities to aid in accelerating aggregations on 128-bit types (#10201) @jlowe
• Fix docstrings alignment in Frame methods (#10199) @galipremsagar
• Fix cuco pair issue in hash join (#10195) @PointKernel
• Replace dask groupby .index usages with .by (#10193) @galipremsagar
• Add regex flags to strings extract function (#10192) @davidwendt
• Forward-merge branch-22.02 to branch-22.04 (#10191) @bdice
• Add CMake install rule for tests (#10190) @ajschmidt8
• Unpin dask & distributed (#10182) @galipremsagar
• Add comments to explain test validation (#10176) @galipremsagar
• Reduce warnings in pytest output (#10168) @bdice
• Some consolidation of indexed frame methods (#10167) @vyasr
• Refactor isin implementations (#10165) @vyasr
• Faster struct row comparator (#10164) @devavret
• Refactor groupby::get_groups. (#10161) @bdice
• Deprecate decimal_cols_as_float in ORC reader (C++ layer) (#10152) @vuule
• Replace ccache with sccache (#10146) @ajschmidt8
• Murmur3 hash kernel cleanup (#10143) @rwlee
• Deprecate decimal_cols_as_float in ORC reader (#10142) @galipremsagar
• Run pyupgrade 2.31.0. (#10141) @bdice
• Remove drop_nan from internal IndexedFrame._drop_na_rows. (#10140) @bdice
• Change cudf::strings::find_multiple to return a lists column (#10134) @davidwendt
• Update cmake-format script for branch 22.04. (#10132) @bdice
• Accept r-value references in convert_table_for_return(): (#10131) @mythrocks
• Remove the option to completely disable decimal128 columns in the ORC reader (#10127) @vuule
• Remove deprecated code (#10124) @vyasr
• Update gpu_utils.py to reflect current CUDA support. (#10113) @bdice
• Remove benchmarks suffix (#10112) @bdice
• Update cudf java binding version to 22.04.0-SNAPSHOT (#10084) @pxLi
• Remove unnecessary docker files. (#10069) @vyasr
• Limit benchmark iterations using environment variable (#10060) @karthikeyann
• Add timing chart for libcudf build metrics report page (#10038) @davidwendt
• JNI: Rewrite growBuffersAndRows to accelerate the HostColumnBuilder (#10025) @sperlingxx
• Reduce redundant code in CUDF JNI (#10019) @mythrocks
• Make snappy decompress check more efficient (#9995) @cheinger
• Remove deprecated method Series.set_index. (#9945) @bdice
• Implement a mixin for reductions (#9925) @vyasr
• JNI: Push back decimal utils from spark-rapids (#9907) @sperlingxx
• Add assert_column_memory_* (#9882) @isVoid
• Add CUDF_UNREACHABLE macro. (#9727) @bdice
• Upgrade arrow & pyarrow to 6.0.1 (#9686) @galipremsagar

🚨 Breaking Changes

• ORC writer API changes for granular statistics (#10058) @mythrocks
• decimal128 Support for to/from_arrow (#9986) @codereport
• Remove deprecated method one_hot_encoding (#9977) @isVoid
• Remove str.subword_tokenize (#9968) @VibhuJawa
• Remove deprecated method parameter from merge and join. (#9944) @bdice
• Remove deprecated method DataFrame.hash_columns. (#9943) @bdice
• Remove deprecated method Series.hash_encode. (#9942) @bdice
• Refactoring ceil/round/floor code for datetime64 types (#9926) @mayankanand007
• Introduce nan_as_null parameter for cudf.Index (#9893) @galipremsagar
• Add regex_flags parameter to strings replace_re functions (#9878) @davidwendt
• Break tie for top categorical columns in Series.describe (#9867) @isVoid
• Add partitioning support in parquet writer (#9810) @devavret
• Move drop_duplicates, drop_na, _gather, take to IndexFrame and create their _base_index counterparts (#9807) @isVoid
• Raise temporary error for decimal128 types in parquet reader (#9804) @galipremsagar
• Change default dtype of all nulls column from float to object (#9803) @galipremsagar
• Remove unused masked udf cython/c++ code (#9792) @brandon-b-miller
• Pick smallest decimal type with required precision in ORC reader (#9775) @vuule
• Add decimal128 support to Parquet reader and writer (#9765) @vuule
• Refactor TableTest assertion methods to a separate utility class (#9762) @jlowe
• Use cuFile direct device reads/writes by default in cuIO (#9722) @vuule
• Match pandas scalar result types in reductions (#9717) @brandon-b-miller
• Add parameters to control row group size in Parquet writer (#9677) @vuule
• Refactor bit counting APIs, introduce valid/null count functions, and split host/device side code for segmented counts. (#9588) @bdice
• Add support for decimal128 in cudf python (#9533) @galipremsagar
• Implement lists::index_of() to find positions in list rows (#9510) @mythrocks
• Rewriting row/column conversions for Spark <-> cudf data conversions (#8444) @hyperbolic2346

🐛 Bug Fixes

• Add check for negative stripe index in ORC reader (#10074) @vuule
• Update Java tests to expect DECIMAL128 from Arrow (#10073) @jlowe
• Avoid index materialization when DataFrame is created with un-named Series objects (#10071) @galipremsagar
• fix gcc 11 compilation errors (#10067) @rongou
• Fix columns ordering issue in parquet reader (#10066) @galipremsagar
• Fix dataframe setitem with ndarray types (#10056) @galipremsagar
• Remove implicit copy due to conversion from cudf::size_type and size_t (#10045) @robertmaynard
• Include <optional> in headers that use std::optional (#10044) @robertmaynard
• Fix repr and concat of StructColumn (#10042) @galipremsagar
• Include row group level stats when writing ORC files (#10041) @vuule
• build.sh respects the --build_metrics and --incl_cache_stats flags (#10035) @robertmaynard
• Fix memory leaks in JNI native code. (#10029) @mythrocks
• Update JNI to use new arena mr constructor (#10027) @rongou
• Fix null check when comparing structs in arg_min operation of reduction/groupby (#10026) @ttnghia
• Wrap CI script shell variables in quotes to fix local testing. (#10018) @bdice
• cudftestutil no longer propagates compiler flags to external users (#10017) @robertmaynard
• Remove CUDA_DEVICE_CALLABLE macro usage (#10015) @hyperbolic2346
• Add missing list filling header in meta.yaml (#10007) @devavret
• Fix conda recipes for custreamz & cudf_kafka (#10003) @ajschmidt8
• Fix matching regex word-boundary (\b) in strings replace (#9997) @davidwendt
• Fix null check when comparing structs in min and max reduction/groupby operations (#9994) @ttnghia
• Fix octal pattern matching in regex string (#9993) @davidwendt
• decimal128 Support for to/from_arrow (#9986) @codereport
• Fix groupby shift/diff/fill after selecting from a GroupBy (#9984) @shwina
• Fix the overflow problem of decimal rescale (#9966) @sperlingxx
• Use default value for decimal precision in parquet writer when not specified (#9963) @devavret
• Fix cudf java build error. (#9958) @firestarman
• Use gpuci_mamba_retry to install local artifacts. (#9951) @bdice
• Fix regression HostColumnVectorCore requiring native libs (#9948) @jlowe
• Rename aggregate_metadata in writer to fix name collision (#9938) @devavret
• Fixed issue with percentile_approx where output tdigests could have uninitialized data at the end. (#9931) @nvdbaranec
• Resolve racecheck errors in ORC kernels (#9916) @vuule
• Fix the java build after parquet partitioning support (#9908) @revans2
• Fix compilation of benchmark for parquet writer. (#9905) @bdice
• Fix a memcheck error in ORC writer (#9896) @vuule
• Introduce nan_as_null parameter for cudf.Index (#9893) @galipremsagar
• Fix fallback to sort aggregation for grouping only hash aggregate (#9891) @abellina
• Add zlib to cudfjni link when using static libcudf library dependency (#9890) @jlowe
• TimedeltaIndex constructor raises an AttributeError. (#9884) @skirui-source
• Fix cudf.Scalar string datetime construction (#9875) @brandon-b-miller
• Load libcufile.so with RTLD_NODELETE flag (#9872) @vuule
• Break tie for top categorical columns in Series.describe (#9867) @isVoid
• Fix null handling for structs min and arg_min in groupby, groupby scan, reduction, and inclusive_scan (#9864) @ttnghia
• Add one-level list encoding support in parquet reader (#9848) @PointKernel
• Fix an out-of-bounds read in validity copying in contiguous_split. (#9842) @nvdbaranec
• Fix join of MultiIndex to Index with one column and overlapping name. (#9830) @vyasr
• Fix caching in Series.applymap (#9821) @brandon-b-miller
• Enforce boolean ascending for dask-cudf sort_values (#9814) @charlesbluca
• Fix ORC writer crash with empty input columns (#9808) @vuule
• Change default dtype of all nulls column from float to object (#9803) @galipremsagar
• Load native dependencies when Java ColumnView is loaded (#9800) @jlowe
• Fix dtype-argument bug in dask_cudf read_csv (#9796) @rjzamora
• Fix overflow for min calculation in strings::from_timestamps (#9793) @revans2
• Fix memory error due to lambda return type deduction limitation (#9778) @karthikeyann
• Revert regex $/EOL end-of-string new-line special case handling (#9774) @davidwendt
• Fix missing streams (#9767) @karthikeyann
• Fix make_empty_scalar_like on list_type (#9759) @sperlingxx
• Update cmake and conda to 22.02 (#9746) @devavret
• Fix out-of-bounds memory write in decimal128-to-string conversion (#9740) @davidwendt
• Match pandas scalar result types in reductions (#9717) @brandon-b-miller
• Fix regex non-multiline EOL/$ matching strings ending with a new-line (#9715) @davidwendt
• Fixed build by adding more checks for int8, int16 (#9707) @razajafri
• Fix null handling when boolean dtype is passed (#9691) @galipremsagar
• Fix stream usage in segmented_gather() (#9679) @mythrocks

📖 Documentation

• Update decimal dtypes related docs entries (#10072) @galipremsagar
• Fix regex doc describing hexadecimal escape characters (#10009) @davidwendt
• Fix cudf compilation instructions. (#9956) @esoha-nvidia
• Fix see also links for IO APIs (#9895) @galipremsagar
• Fix build instructions for libcudf doxygen (#9837) @davidwendt
• Fix some doxygen warnings and add missing documentation (#9770) @karthikeyann
• update cuda version in local build (#9736) @karthikeyann
• Fix doxygen for enum types in libcudf (#9724) @davidwendt
• Spell check fixes (#9682) @karthikeyann
• Fix links in C++ Developer Guide. (#9675) @bdice

🚀 New Features

• Remove libcudacxx patch needed for nvcc 11.4 (#10057) @robertmaynard
• Allow CuPy 10 (#10048) @jakirkham
• Add in support for NULL_LOGICAL_AND and NULL_LOGICAL_OR binops (#10016) @revans2
• Add groupby.transform (only support for aggregations) (#10005) @shwina
• Add partitioning support to Parquet chunked writer (#10000) @devavret
• Add jni for sequences (#9972) @wbo4958
• Java bindings for mixed left, inner, and full joins (#9941) @jlowe
• Java bindings for JSON reader support (#9940) @wbo4958
• Enable transpose for string columns in cudf python (#9937) @galipremsagar
• Support structs for cudf::contains with column/scalar input (#9929) @ttnghia
• Implement mixed equality/conditional joins (#9917) @vyasr
• Add cudf::strings::extract_all API (#9909) @davidwendt
• Implement JNI for cudf::scatter APIs (#9903) @ttnghia
• JNI: Function to copy and set validity from bool column. (#9901) @mythrocks
• Add dictionary support to cudf::copy_if_else (#9887) @davidwendt
• add run_benchmarks target for running benchmarks with json output (#9879) @karthikeyann
• Add regex_flags parameter to strings replace_re functions (#9878) @davidwendt
• Add_suffix and add_prefix for DataFrames and Series (#9846) @mayankanand007
• Add JNI for cudf::drop_duplicates (#9841) @ttnghia
• Implement per-list sequence (#9839) @ttnghia
• adding series.transpose (#9835) @mayankanand007
• Adding support for Series.autocorr (#9833) @mayankanand007
• Support round operation on datetime64 datatypes (#9820) @mayankanand007
• Add partitioning support in parquet writer (#9810) @devavret
• Raise temporary error for decimal128 types in parquet reader (#9804) @galipremsagar
• Add decimal128 support to Parquet reader and writer (#9765) @vuule
• Optimize groupby::scan (#9754) @PointKernel
• Add sample JNI API (#9728) @res-life
• Support min and max in inclusive scan for structs (#9725) @ttnghia
• Add first and last method to IndexedFrame (#9710) @isVoid
• Support min and max reduction for structs (#9697) @ttnghia
• Add parameters to control row group size in Parquet writer (#9677) @vuule
• Run compute-sanitizer in nightly build (#9641) @karthikeyann
• Implement Series.datetime.floor (#9571) @skirui-source
• ceil/floor for DatetimeIndex (#9554) @mayankanand007
• Add support for decimal128 in cudf python (#9533) @galipremsagar
• Implement lists::index_of() to find positions in list rows (#9510) @mythrocks
• custreamz oauth callback for kafka (librdkafka) (#9486) @jdye64
• Add Pearson correlation for sort groupby (python) (#9166) @skirui-source
• Interchange dataframe protocol (#9071) @iskode
• Rewriting row/column conversions for Spark <-> cudf data conversions (#8444) @hyperbolic2346

🛠️ Improvements

• Prepare upload scripts for Python 3.7 removal (#10092) @Ethyling
• Simplify custreamz and cudf_kafka recipes files (#10065) @Ethyling
• ORC writer API changes for granular statistics (#10058) @mythrocks
• Remove python constraints in cutreamz and cudf_kafka recipes (#10052) @Ethyling
• Unpin dask and distributed in CI (#10028) @galipremsagar
• Add _from_column_like_self factory (#10022) @isVoid
• Replace custom CUDA bindings previously provided by RMM with official CUDA Python bindings (#10008) @shwina
• Use cuda::std::is_arithmetic in cudf::is_numeric trait. (#9996) @bdice
• Clean up CUDA stream use in cuIO (#9991) @vuule
• Use addressed-ordered first fit for the pinned memory pool (#9989) @rongou
• Add strings tests to transpose_test.cpp (#9985) @davidwendt
• Use gpuci_mamba_retry on Java CI. (#9983) @bdice
• Remove deprecated method one_hot_encoding (#9977) @isVoid
• Minor cleanup of unused Python functions (#9974) @vyasr
• Use new efficient partitioned parquet writing in cuDF (#9971) @devavret
• Remove str.subword_tokenize (#9968) @VibhuJawa
• Forward-merge branch-21.12 to branch-22.02 (#9947) @bdice
• Remove deprecated method parameter from merge and join. (#9944) @bdice
• Remove deprecated method DataFrame.hash_columns. (#9943) @bdice
• Remove deprecated method Series.hash_encode. (#9942) @bdice
• use ninja in java ci build (#9933) @rongou
• Add build-time publish step to cpu build script (#9927) @davidwendt
• Refactoring ceil/round/floor code for datetime64 types (#9926) @mayankanand007
• Remove various unused functions (#9922) @vyasr
• Raise in query if dtype is not supported (#9921) @brandon-b-miller
• Add missing imports tests (#9920) @Ethyling
• Spark Decimal128 hashing (#9919) @rwlee
• Replace thrust/std::get with structured bindings (#9915) @codereport
• Upgrade thrust version to 1.15 (#9912) @robertmaynard
• Remove conda envs for CUDA 11.0 and 11.2. (#9910) @bdice
• Return count of set bits from inplace_bitmask_and. (#9904) @bdice
• Use dynamic nullate for join hasher and equality comparator (#9902) @davidwendt
• Update ucx-py version on release using rvc (#9897) @Ethyling
• Remove IncludeCategories from .clang-format (#9876) @codereport
• Support statically linking CUDA runtime for Java bindings (#9873) @jlowe
• Add clang-tidy to libcudf (#9860) @codereport
• Remove deprecated methods from Java Table class (#9853) @jlowe
• Add test for map column metadata handling in ORC writer (#9852) @vuule
• Use pandas to_offset to parse frequency string in date_range (#9843) @isVoid
• add templated benchmark with fixture (#9838) @karthikeyann
• Use list of column inputs for apply_boolean_mask (#9832) @isVoid
• Added a few more tests for Decimal to String cast (#9818) @razajafri
• Run doctests. (#9815) @bdice
• Avoid overflow for fixed_point round (#9809) @sperlingxx
• Move drop_duplicates, drop_na, _gather, take to IndexFrame and create their _base_index counterparts (#9807) @isVoid
• Use vector factories for host-device copies. (#9806) @bdice
• Refactor host device macros (#9797) @vyasr
• Remove unused masked udf cython/c++ code (#9792) @brandon-b-miller
• Allow custom sort functions for dask-cudf sort_values (#9789) @charlesbluca
• Improve build time of libcudf iterator tests (#9788) @davidwendt
• Copy Java native dependencies directly into classpath (#9787) @jlowe
• Add decimal types to cuIO benchmarks (#9776) @vuule
• Pick smallest decimal type with required precision in ORC reader (#9775) @vuule
• Avoid overflow for fixed_point cudf::cast and performance optimization (#9772) @codereport
• Use CTAD with Thrust function objects (#9768) @codereport
• Refactor TableTest assertion methods to a separate utility class (#9762) @jlowe
• Use Java classloader to find test resources (#9760) @jlowe
• Allow cast decimal128 to string and add tests (#9756) @razajafri
• Load balance optimization for contiguous_split (#9755) @nvdbaranec
• Consolidate and improve reset_index (#9750) @isVoid
• Update to UCX-Py 0.24 (#9748) @pentschev
• Skip cufile tests in JNI build script (#9744) @pxLi
• Enable string to decimal 128 cast (#9742) @razajafri
• Use stop instead of stop_. (#9735) @bdice
• Forward-merge branch-21.12 to branch-22.02 (#9730) @bdice
• Improve cmake format script (#9723) @vyasr
• Use cuFile direct device reads/writes by default in cuIO (#9722) @vuule
• Add directory-partitioned data support to cudf.read_parquet (#9720) @rjzamora
• Use stream allocator adaptor for hash join table (#9704) @PointKernel
• Update check for inf/nan strings in libcudf float conversion to ignore case (#9694) @davidwendt
• Update cudf JNI to 22.02.0-SNAPSHOT (#9681) @pxLi
• Replace cudf's concurrent_ordered_map with cuco::static_map in semi/anti joins (#9666) @vyasr
• Some improvements to parse_decimal function and bindings for is_fixed_point (#9658) @razajafri
• Add utility to format ninja-log build times (#9631) @davidwendt
• Allow runtime has_nulls parameter for row operators (#9623) @davidwendt
• Use fsspec.parquet for improved read_parquet performance from remote storage (#9589) @rjzamora
• Refactor bit counting APIs, introduce valid/null count functions, and split host/device side code for segmented counts. (#9588) @bdice
• Use List of Columns as Input for drop_nulls, gather and drop_duplicates (#9558) @isVoid
• Simplify merge internals and reduce overhead (#9516) @vyasr
• Add struct generation support in datagenerator & fuzz tests (#9180) @galipremsagar
• Simplify write_csv by removing unnecessary writer/impl classes (#9089) @cwharris

v21.12.02

v21.12.01

🚨 Breaking Changes

• Update bitmask_and and bitmask_or to return a pair of resulting mask and count of unset bits (#9616) @PointKernel
• Remove sizeof and standardize on memory_usage (#9544) @vyasr
• Add support for single-line regex anchors ^/$ in contains_re (#9482) @davidwendt
• Refactor sorting APIs (#9464) @vyasr
• Update Java nvcomp JNI bindings to nvcomp 2.x API (#9384) @jbrennan333
• Support Python UDFs written in terms of rows (#9343) @brandon-b-miller
• JNI: Support nested types in ORC writer (#9334) @firestarman
• Optionally nullify out-of-bounds indices in segmented_gather(). (#9318) @mythrocks
• Refactor cuIO timestamp processing with cuda::std::chrono (#9278) @PointKernel
• Various internal MultiIndex improvements (#9243) @vyasr

🐛 Bug Fixes

• Fix read_parquet bug for bytes input (#9669) @rjzamora
• Use _gather internal for sort_* (#9668) @isVoid
• Fix behavior of equals for non-DataFrame Frames and add tests. (#9653) @vyasr
• Dont recompute output size if it is already available (#9649) @abellina
• Fix read_parquet bug for extended dtypes from remote storage (#9638) @rjzamora
• add const when getting data from a JNI data wrapper (#9637) @wjxiz1992
• Fix debrotli issue on CUDA 11.5 (#9632) @vuule
• Use std::size_t when computing join output size (#9626) @jlowe
• Fix usecols parameter handling in dask_cudf.read_csv (#9618) @galipremsagar
• Add support for string 'nan', 'inf' & '-inf' values while type-casting to float (#9613) @galipremsagar
• Avoid passing NativeFileDatasource to pyarrow in read_parquet (#9608) @rjzamora
• Fix test failure with cuda 11.5 in row_bit_count tests. (#9581) @nvdbaranec
• Correct _LIBCUDACXX_CUDACC_VER value computation (#9579) @robertmaynard
• Increase max RLE stream size estimate to avoid potential overflows (#9568) @vuule
• Fix edge case in tdigest scalar generation for groups containing all nulls. (#9551) @nvdbaranec
• Fix pytests failing in cuda-11.5 environment (#9547) @galipremsagar
• compile libnvcomp with PTDS if requested (#9540) @jbrennan333
• Fix segmented_gather() for null LIST rows (#9537) @mythrocks
• Deprecate DataFrame.label_encoding, use private _label_encoding method internally. (#9535) @bdice
• Fix several test and benchmark issues related to bitmask allocations. (#9521) @nvdbaranec
• Fix for inserting duplicates in groupby result cache (#9508) @karthikeyann
• Fix mismatched types error in clip() when using non int64 numeric types (#9498) @davidwendt
• Match conda pinnings for style checks (revert part of #9412, #9433). (#9490) @bdice
• Make sure all dask-cudf supported aggs are handled in _tree_node_agg (#9487) @charlesbluca
• Resolve hash_columns FutureWarning in dask_cudf (#9481) @pentschev
• Add fixed point to AllTypes in libcudf unit tests (#9472) @karthikeyann
• Fix regex handling of embedded null characters (#9470) @davidwendt
• Fix memcheck error in copy-if-else (#9467) @davidwendt
• Fix bug in dask_cudf.read_parquet for index=False (#9453) @rjzamora
• Preserve the decimal scale when creating a default scalar (#9449) @revans2
• Push down parent nulls when flattening nested columns. (#9443) @mythrocks
• Fix memcheck error in gtest SegmentedGatherTest/GatherSliced (#9442) @davidwendt
• Revert "Fix quantile division / partition handling for dask-cudf sort… (#9438) @charlesbluca
• Allow int-like objects for the decimals argument in round (#9428) @shwina
• Fix stream compaction's drop_duplicates API to use stable sort (#9417) @ttnghia
• Skip Comparing Uniform Window Results in Var/std Tests (#9416) @isVoid
• Fix StructColumn.to_pandas type handling issues (#9388) @galipremsagar
• Correct issues in the build dir cudf-config.cmake (#9386) @robertmaynard
• Fix Java table partition test to account for non-deterministic ordering (#9385) @jlowe
• Fix timestamp truncation/overflow bugs in orc/parquet (#9382) @PointKernel
• Fix the crash in stats code (#9368) @devavret
• Make Series.hash_encode results reproducible. (#9366) @bdice
• Fix libcudf compile warnings on debug 11.4 build (#9360) @davidwendt
• Fail gracefully when compiling python UDFs that attempt to access columns with unsupported dtypes (#9359) @brandon-b-miller
• Set pass_filenames: false in mypy pre-commit configuration. (#9349) @bdice
• Fix cudf_assert in cudf::io::orc::gpu::gpuDecodeOrcColumnData (#9348) @davidwendt
• Fix memcheck error in groupby-tdigest get_scalar_minmax (#9339) @davidwendt
• Optimizations for cudf.concat when axis=1 (#9333) @galipremsagar
• Use f-string in join helper warning message. (#9325) @bdice
• Avoid casting to list or struct dtypes in dask_cudf.read_parquet (#9314) @rjzamora
• Fix null count in statistics for parquet (#9303) @devavret
• Potential overflow of decimal32 when casting to int64_t (#9287) @codereport
• Fix quantile division / partition handling for dask-cudf sort on null dataframes (#9259) @charlesbluca
• Updating cudf version also updates rapids cmake branch (#9249) @robertmaynard
• Implement one_hot_encoding in libcudf and bind to python (#9229) @isVoid
• BUG FIX: CSV Writer ignores the header parameter when no metadata is provided (#8740) @skirui-source

📖 Documentation

• Update Documentation to use TYPED_TEST_SUITE (#9654) @codereport
• Add dedicated page for StringHandling in python docs (#9624) @galipremsagar
• Update docstring of DataFrame.merge (#9572) @galipremsagar
• Use raw strings to avoid SyntaxErrors in parsed docstrings. (#9526) @bdice
• Add example to docstrings in rolling.apply (#9522) @isVoid
• Update help message to escape quotes in ./build.sh --cmake-args. (#9494) @bdice
• Improve Python docstring formatting. (#9493) @bdice
• Update table of I/O supported types (#9476) @vuule
• Document invalid regex patterns as undefined behavior (#9473) @davidwendt
• Miscellaneous documentation fixes to cudf (#9471) @galipremsagar
• Fix many documentation errors in libcudf. (#9355) @karthikeyann
• Fixing SubwordTokenizer docs issue (#9354) @mayankanand007
• Improved deprecation warnings. (#9347) @bdice
• doc reorder mr, stream to stream, mr (#9308) @karthikeyann
• Deprecate method parameters to DataFrame.join, DataFrame.merge. (#9291) @bdice
• Added deprecation warning for .label_encoding() (#9289) @mayankanand007

🚀 New Features

• Enable Series.divide and DataFrame.divide (#9630) @vyasr
• Update bitmask_and and bitmask_or to return a pair of resulting mask and count of unset bits (#9616) @PointKernel
• Add handling of mixed numeric types in to_dlpack (#9585) @galipremsagar
• Support re.Pattern object for pat arg in str.replace (#9573) @davidwendt
• Add JNI for lists::drop_list_duplicates with keys-values input column (#9553) @ttnghia
• Support structs column in min, max, argmin and argmax groupby aggregate() and scan() (#9545) @ttnghia
• Move libcudacxx to use rapids_cpm and use newer versions (#9539) @robertmaynard
• Add scan min/max support for chrono types to libcudf reduction-scan (not groupby scan) (#9518) @davidwendt
• Support args= in apply (#9514) @brandon-b-miller
• Add groupby scan min/max support for strings values (#9502) @davidwendt
• Add list output option to character_ngrams() function (#9499) @davidwendt
• More granular column selection in ORC reader (#9496) @vuule
• add min_periods, ddof to groupby covariance, & correlation aggregation (#9492) @karthikeyann
• Implement Series.datetime.floor (#9488) @skirui-source
• Enable linting of CMake files using pre-commit (#9484) @vyasr
• Add support for single-line regex anchors ^/$ in contains_re (#9482) @davidwendt
• Augment order_by to Accept a List of null_precedence (#9455) @isVoid
• Add format API for list column of strings (#9454) @davidwendt
• Enable Datetime/Timedelta dtypes in Masked UDFs (#9451) @brandon-b-miller
• Add cudf python groupby.diff (#9446) @karthikeyann
• Implement lists::stable_sort_lists for stable sorting of elements within each row of lists column (#9425) @ttnghia
• add ctest memcheck using cuda-sanitizer (#9414) @karthikeyann
• Support Unary Operations in Masked UDF (#9409) @isVoid
• Move Several Series Function to Frame (#9394) @isVoid
• MD5 Python hash API (#9390) @bdice
• Add cudf strings is_title API (#9380) @davidwendt
• Enable casting to int64, uint64, and double in AST code. (#9379) @vyasr
• Add support for writing ORC with map columns (#9369) @vuule
• extract_list_elements() with column_view indices (#9367) @mythrocks
• Reimplement lists::drop_list_duplicates for keys-values lists columns (#9345) @ttnghia
• Support Python UDFs written in terms of rows (#9343) @brandon-b-miller
• JNI: Support nested types in ORC writer (#9334) @firestarman
• Optionally nullify out-of-bounds indices in segmented_gather(). (#9318) @mythrocks
• Add shallow hash function and shallow equality comparison for column_view (#9312) @karthikeyann
• Add CudaMemoryBuffer for cudaMalloc memory using RMM cuda_memory_resource (#9311) @rongou
• Add parameters to control row index stride and stripe size in ORC writer (#9310) @vuule
• Add na_position param to dask-cudf sort_values (#9264) @charlesbluca
• Add ascending parameter for dask-cudf sort_values (#9250) @charlesbluca
• New array conversion methods (#9236) @vyasr
• Series apply method backed by masked UDFs (#9217) @brandon-b-miller
• Grouping by frequency and resampling (#9178) @shwina
• Pure-python masked UDFs (#9174) @brandon-b-miller
• Add Covariance, Pearson correlation for sort groupby (libcudf) (#9154) @karthikeyann
• Add calendrical_month_sequence in c++ and date_range in python (#8886) @shwina

🛠️ Improvements

• Followup to PR 9088 comments (#9659) @cwharris
• Update cuCollections to version that supports installed libcudacxx (#9633) @robertmaynard
• Add 11.5 dev.yml to cudf (#9617) @galipremsagar
• Add xfail for parquet reader 11.5 issue (#9612) @galipremsagar
• remove deprecated Rmm.initialize method (#9607) @rongou
• Use HostColumnVectorCore for child columns in JCudfSerialization.unpackHostColumnVectors (#9596) @sperlingxx
• Set RMM pool to a fixed size in JNI (#9583) @rongou
• Use nvCOMP for Snappy compression/decompression (#9582) @vuule
• Build CUDA version agnostic packages for dask-cudf (#9578) @Ethyling
• Fixed tests warning: "TYPED_TEST_CASE is deprecated, please use TYPED_TEST_SUITE" (#9574) @ttnghia
• Enable CMake format in CI and fix style (#9570) @vyasr
• Add NVTX Start/End Ranges to JNI (#9563) @abellina
• Add librdkafka and python-confluent-kafka to dev conda environments s… (#9562) @jdye64
• Add offsets_begin/end() to strings_column_view (#9559) @davidwendt
• remove alignment options for RMM jni (#9550) @rongou
• Add axis parameter passthrough to DataFrame and Series take for pandas API compatibility (#9549) @dantegd
• Remove sizeof and standardize on memory_usage (#9544) @vyasr
• Adds cudaProfilerStart/cudaProfilerStop in JNI api (#9543) @abellina
• Generalize comparison binary operations (#9542) @vyasr
• Expose APIs to wrap CUDA or RMM allocations with a Java device buffer instance (#9538) @jlowe
• Add scan sum support for duration types to libcudf (#9536) @davidwendt
• Force inlining to improve AST performance (#9530) @vyasr
• Generalize some more indexed frame methods (#9529) @vyasr
• Add Java bindings for rolling window stddev aggregation (#9527) @razajafri
• catch rmm::out_of_memory exceptions in jni (#9525) @rongou
• Add an overload of make_empty_column with type_id parameter (#9524) @ttnghia
• Accelerate conditional inner joins with larger right tables (#9523) @vyasr
• Initial pass of generalizing decimal support in cudf python layer (#9517) @galipremsagar
• Cleanup for flattening nested columns (#9509) @rwlee
• Enable running tests using RMM arena and async memory resources (#9506) @rongou
• Remove dependency on six. (#9495) @bdice
• Cleanup some libcudf strings gtests (#9489) @davidwendt
• Rename strings/array_tests.cu to strings/array_tests.cpp (#9480) @davidwendt
• Refactor sorting APIs (#9464) @vyasr
• Implement DataFrame.hash_values, deprecate DataFrame.hash_columns. (#9458) @bdice
• Deprecate Series.hash_encode. (#9457) @bdice
• Update conda recipes for Enhanced Compatibility effort (#9456) @ajschmidt8
• Small clean up to simplify column selection code in ORC reader (#9444) @vuule
• add missing stream to scalar.is_valid() wherever stream is available (#9436) @karthikeyann
• Adds Deprecation Warnings to one_hot_encoding and Implement get_dummies with Cython API (#9435) @isVoid
• Update pre-commit hook URLs. (#9433) @bdice
• Remove pyarrow import in dask_cudf.io.parquet (#9429) @charlesbluca
• Miscellaneous improvements for UDFs (#9422) @isVoid
• Use pre-commit for CI (#9412) @vyasr
• Update to UCX-Py 0.23 (#9407) @pentschev
• Expose OutOfBoundsPolicy in JNI for Table.gather (#9406) @abellina
• Improvements to tdigest aggregation code. (#9403) @nvdbaranec
• Add Java API to deserialize a table to host columns (#9402) @jlowe
• Frame copy to use class instead of type() (#9397) @madsbk
• Change all DeprecationWarnings to FutureWarning. (#9392) @bdice
• Update Java nvcomp JNI bindings to nvcomp 2.x API (#9384) @jbrennan333
• Add IndexedFrame class and move SingleColumnFrame to a separate module (#9378) @vyasr
• Support Arrow NativeFile and PythonFile for remote ORC storage (#9377) @rjzamora
• Use Arrow PythonFile for remote CSV storage (#9376) @rjzamora
• Add multi-threaded writing to GDS writes (#9372) @devavret
• Miscellaneous column cleanup (#9370) @vyasr
• Use single kernel to extract all groups in cudf::strings::extract (#9358) @davidwendt
• Consolidate binary ops into Frame (#9357) @isVoid
• Move rank scan implementations from scan_inclusive.cu to rank_scan.cu (#9351) @davidwendt
• Remove usage of deprecated thrust::host_space_tag. (#9350) @bdice
• Use Default Memory Resource for Temporaries in reduction.cpp (#9344) @isVoid
• Fix Cython compilation warnings. (#9327) @bdice
• Fix some unused variable warnings in libcudf (#9326) @davidwendt
• Use optional-iterator for copy-if-else kernel (#9324) @davidwendt
• Remove Table class (#9315) @vyasr
• Unpin dask and distributed in CI (#9307) @galipremsagar
• Add optional-iterator support to indexalator (#9306) @davidwendt
• Consolidate more methods in Frame (#9305) @vyasr
• Add Arrow-NativeFile and PythonFile support to read_parquet and read_csv in cudf (#9304) @rjzamora
• Pin mypy in .pre-commit-config.yaml to match conda environment pinning. (#9300) @bdice
• Use gather.hpp when gather-map exists in device memory (#9299) @davidwendt
• Fix Automerger for Branch-21.12 from branch-21.10 (#9285) @galipremsagar
• Refactor cuIO timestamp processing with cuda::std::chrono (#9278) @PointKernel
• Change strings copy_if_else to use optional-iterator instead of pair-iterator (#9266) @davidwendt
• Update cudf java bindings to 21.12.0-SNAPSHOT (#9248) @pxLi
• Various internal MultiIndex improvements (#9243) @vyasr
• Add detail interface for split and slice(table_view), refactors both function with host_span (#9226) @isVoid
• Refactor MD5 implementation. (#9212) @bdice
• Update groupby result_cache to allow sharing intermediate results based on column_view instead of requests. (#9195) @karthikeyann
• Use nvcomp's snappy decompressor in avro reader (#9181) @devavret
• Add isocalendar API support (#9169) @marlenezw
• Simplify read_json by removing unnecessary reader/impl classes (#9088) @cwharris
• Simplify read_csv by removing unnecessary reader/impl classes (#9041) @cwharris
• Refactor hash join with cuCollections multimap (#8934) @PointKernel

v21.10.01

🚨 Breaking Changes

• Remove Cython APIs for table view generation (#9199) @vyasr
• Upgrade pandas version in cudf (#9147) @galipremsagar
• Make AST operators nullable (#9096) @vyasr
• Remove the option to pass data types as strings to read_csv and read_json (#9079) @vuule
• Update JNI java CSV APIs to not use deprecated API (#9066) @revans2
• Support additional format specifiers in from_timestamps (#9047) @davidwendt
• Expose expression base class publicly and simplify public AST API (#9045) @vyasr
• Add support for struct type in ORC writer (#9025) @vuule
• Remove aliases of various api.types APIs from utils.dtypes. (#9011) @vyasr
• Java bindings for conditional join output sizes (#9002) @jlowe
• Move compute_column API out of ast namespace (#8957) @vyasr
• cudf.dtype function (#8949) @shwina
• Refactor Frame reductions (#8944) @vyasr
• Add nested column selection to parquet reader (#8933) @devavret
• JNI Aggregation Type Changes (#8919) @revans2
• Add groupby_aggregation and groupby_scan_aggregation classes and force their usage. (#8906) @nvdbaranec
• Expand CSV and JSON reader APIs to accept dtypes as a vector or map of data_type objects (#8856) @vuule
• Change cudf docs theme to pydata theme (#8746) @galipremsagar
• Enable compiled binary ops in libcudf, python and java (#8741) @karthikeyann
• Make groupby transform-like op order match original data order (#8720) @isVoid

🐛 Bug Fixes

• fixed_point cudf::groupby for mean aggregation (#9296) @codereport
• Fix interleave_columns when the input string lists column having empty child column (#9292) @ttnghia
• Update nvcomp to include fixes for installation of headers (#9276) @devavret
• Fix Java column leak in testParquetWriteMap (#9271) @jlowe
• Fix call to thrust::reduce_by_key in argmin/argmax libcudf groupby (#9263) @davidwendt
• Fixing empty input to getMapValue crashing (#9262) @hyperbolic2346
• Fix duplicate names issue in MultiIndex.deserialize (#9258) @galipremsagar
• Dataframe.sort_index optimizations (#9238) @galipremsagar
• Temporarily disabling problematic test in parquet writer (#9230) @devavret
• Explicitly disable groupby on unsupported key types. (#9227) @mythrocks
• Fix gather for sliced input structs column (#9218) @ttnghia
• Fix JNI code for left semi and anti joins (#9207) @jlowe
• Only install thrust when using a non 'system' version (#9206) @robertmaynard
• Remove zlib from libcudf public CMake dependencies (#9204) @robertmaynard
• Fix out-of-bounds memory read in orc gpuEncodeOrcColumnData (#9196) @davidwendt
• Fix gather() for STRUCT inputs with no nulls in members. (#9194) @mythrocks
• get_cucollections properly uses rapids_cpm_find (#9189) @robertmaynard
• rapids-export correctly reference build code block and doc strings (#9186) @robertmaynard
• Fix logic while parsing the sum statistic for numerical orc columns (#9183) @ayushdg
• Add handling for nulls in dask_cudf.sorting.quantile_divisions (#9171) @charlesbluca
• Approximate overflow detection in ORC statistics (#9163) @vuule
• Use decimal precision metadata when reading from parquet files (#9162) @shwina
• Fix variable name in Java build script (#9161) @jlowe
• Import rapids-cmake modules using the correct cmake variable. (#9149) @robertmaynard
• Fix conditional joins with empty left table (#9146) @vyasr
• Fix joining on indexes with duplicate level names (#9137) @shwina
• Fixes missing child column name in dtype while reading ORC file. (#9134) @rgsl888prabhu
• Apply type metadata after column is slice-copied (#9131) @isVoid
• Fix a bug: inner_join_size return zero if build table is empty (#9128) @PointKernel
• Fix multi hive-partition parquet reading in dask-cudf (#9122) @rjzamora
• Support null literals in expressions (#9117) @vyasr
• Fix cudf::hash_join output size for struct joins (#9107) @jlowe
• Import fix (#9104) @shwina
• Fix cudf::strings::is_fixed_point checking of overflow for decimal32 (#9093) @davidwendt
• Fix branch_stack calculation in row_bit_count() (#9076) @mythrocks
• Fetch rapids-cmake to work around cuCollection cmake issue (#9075) @jlowe
• Fix compilation errors in groupby benchmarks. (#9072) @nvdbaranec
• Preserve float16 upscaling (#9069) @galipremsagar
• Fix memcheck read error in libcudf contiguous_split (#9067) @davidwendt
• Add support for reading ORC file with no row group index (#9060) @rgsl888prabhu
• Various multiindex related fixes (#9036) @shwina
• Avoid rebuilding cython in build.sh (#9034) @brandon-b-miller
• Add support for percentile dispatch in dask_cudf (#9031) @galipremsagar
• cudf resolve nvcc 11.0 compiler crashes during codegen (#9028) @robertmaynard
• Fetch correct grouping keys agg of dask groupby (#9022) @galipremsagar
• Allow where() to work with a Series and other=cudf.NA (#9019) @sarahyurick
• Use correct index when returning Series from GroupBy.apply() (#9016) @charlesbluca
• Fix Dataframe indexer setitem when array is passed (#9006) @galipremsagar
• Fix ORC reading of files with struct columns that have null values (#9005) @vuule
• Ensure JNI native libraries load when CompiledExpression loads (#8997) @jlowe
• Fix memory read error in get_dremel_data in page_enc.cu (#8995) @davidwendt
• Fix memory write error in get_list_child_to_list_row_mapping utility (#8994) @davidwendt
• Fix debug compile error for csv_test.cpp (#8981) @davidwendt
• Fix memory read/write error in concatenate_lists_ignore_null (#8978) @davidwendt
• Fix concatenation of cudf.RangeIndex (#8970) @galipremsagar
• Java conditional joins should not require matching column counts (#8955) @jlowe
• Fix concatenate empty structs (#8947) @sperlingxx
• Fix cuda-memcheck errors for some libcudf functions (#8941) @davidwendt
• Apply series name to result of SeriesGroupby.apply() (#8939) @charlesbluca
• cdef packed_columns as cppclass instead of struct (#8936) @charlesbluca
• Inserting a cudf.NA into a DataFrame (#8923) @sarahyurick
• Support casting with Pandas dtype aliases (#8920) @sarahyurick
• Allow sort_values to accept same kind values as Pandas (#8912) @sarahyurick
• Enable casting to pandas nullable dtypes (#8889) @brandon-b-miller
• Fix libcudf memory errors (#8884) @karthikeyann
• Throw KeyError when accessing field from struct with nonexistent key (#8880) @NV-jpt
• replace auto with auto& ref for cast<&> (#8866) @karthikeyann
• Add missing include<optional> in binops (#8864) @karthikeyann
• Fix select_dtypes to work when non-class dtypes present in dataframe (#8849) @sarahyurick
• Re-enable JSON tests (#8843) @vuule
• Support header with embedded delimiter in csv writer (#8798) @davidwendt

📖 Documentation

• Add IO docs page in cudf documentation (#9145) @galipremsagar
• use correct namespace in cuio code examples (#9037) @cwharris
• Restructuring Contributing doc (#9026) @iskode
• Update stable version in readme (#9008) @galipremsagar
• Add spans and more include guidelines to libcudf developer guide (#8931) @harrism
• Update Java build instructions to mention Arrow S3 and Docker (#8867) @jlowe
• List GDS-enabled formats in the docs (#8805) @vuule
• Change cudf docs theme to pydata theme (#8746) @galipremsagar

🚀 New Features

• Revert "Add shallow hash function and shallow equality comparison for column_view (#9185)" (#9283) @karthikeyann
• Align DataFrame.apply signature with pandas (#9275) @brandon-b-miller
• Add struct type support for drop_list_duplicates (#9202) @ttnghia
• support CUDA async memory resource in JNI (#9201) @rongou
• Add shallow hash function and shallow equality comparison for column_view (#9185) @karthikeyann
• Superimpose null masks for STRUCT columns. (#9144) @mythrocks
• Implemented bindings for ceil timestamp operation (#9141) @shaneding
• Adding MAP type support for ORC Reader (#9132) @rgsl888prabhu
• Implement interleave_columns for lists with arbitrary nested type (#9130) @ttnghia
• Add python bindings to fixed-size window and groupby rolling.var, rolling.std (#9097) @isVoid
• Make AST operators nullable (#9096) @vyasr
• Java bindings for approx_percentile (#9094) @andygrove
• Add dseries.struct.explode (#9086) @isVoid
• Add support for BaseIndexer in Rolling APIs (#9085) @galipremsagar
• Remove the option to pass data types as strings to read_csv and read_json (#9079) @vuule
• Add handling for nested dicts in dask-cudf groupby (#9054) @charlesbluca
• Added Series.dt.is_quarter_start and Series.dt.is_quarter_end (#9046) @TravisHester
• Support nested types for nth_element reduction (#9043) @sperlingxx
• Update sort groupby to use non-atomic operation (#9035) @karthikeyann
• Add support for struct type in ORC writer (#9025) @vuule
• Implement interleave_columns for structs columns (#9012) @ttnghia
• Add groupby first and last aggregations (#9004) @shwina
• Add DecimalBaseColumn and move as_decimal_column (#9001) @isVoid
• Python/Cython bindings for multibyte_split (#8998) @jdye64
• Support scalar months in add_calendrical_months, extends API to INT32 support (#8991) @isVoid
• Added Series.dt.is_month_end (#8989) @TravisHester
• Support for using tdigests to compute approximate percentiles. (#8983) @nvdbaranec
• Support "unflatten" of columns flattened via flatten_nested_columns(): (#8956) @mythrocks
• Implement timestamp ceil (#8942) @shaneding
• Add nested column selection to parquet reader (#8933) @devavret
• Expose conditional join size calculation (#8928) @vyasr
• Support Nulls in Timeseries Generator (#8925) @isVoid
• Avoid index equality check in _CPackedColumns.from_py_table() (#8917) @charlesbluca
• Add dot product binary op (#8909) @charlesbluca
• Expose days_in_month function in libcudf and add python bindings (#8892) @isVoid
• Series string repeat (#8882) @sarahyurick
• Python binding for quarters (#8862) @shaneding
• Expand CSV and JSON reader APIs to accept dtypes as a vector or map of data_type objects (#8856) @vuule
• Add Java bindings for AST transform (#8846) @jlowe
• Series datetime is_month_start (#8844) @sarahyurick
• Support bracket syntax for cudf::strings::replace_with_backrefs group index values (#8841) @davidwendt
• Support VARIANCE and STD aggregation in rolling op (#8809) @isVoid
• Add quarters to libcudf datetime (#8779) @shaneding
• Linear Interpolation of nans via cupy (#8767) @brandon-b-miller
• Enable compiled binary ops in libcudf, python and java (#8741) @karthikeyann
• Make groupby transform-like op order match original data order (#8720) @isVoid
• multibyte_split (#8702) @cwharris
• Implement JNI for strings:repeat_strings that repeats each string separately by different numbers of times (#8572) @ttnghia

🛠️ Improvements

• Pin max dask and distributed versions to 2021.09.1 (#9286) @galipremsagar
• Optimized fsspec data transfer for remote file-systems (#9265) @rjzamora
• Skip dask-cudf tests on arm64 (#9252) @Ethyling
• Use nvcomp's snappy compressor in ORC writer (#9242) @devavret
• Only run imports tests on x86_64 (#9241) @Ethyling
• Remove unnecessary call to device_uvector::release() (#9237) @harrism
• Use nvcomp's snappy decompression in ORC reader (#9235) @devavret
• Add grouped_rolling test with STRUCT groupby keys. (#9228) @mythrocks
• Optimize cudf.concat for axis=0 (#9222) @galipremsagar
• Fix some libcudf calls not passing the stream parameter (#9220) @davidwendt
• Add min and max bounds for random dataframe generator numeric types (#9211) @galipremsagar
• Improve performance of expression evaluation (#9210) @vyasr
• Misc optimizations in cudf (#9203) @galipremsagar
• Remove Cython APIs for table view generation (#9199) @vyasr
• Add JNI support for drop_list_duplicates (#9198) @revans2
• Update pandas versions in conda recipes and requirements.txt files (#9197) @galipremsagar
• Minor C++17 cleanup of groupby.cu: structured bindings, more concise lambda, etc (#9193) @codereport
• Explicit about bitwidth difference between cudf boolean and arrow boolean (#9192) @isVoid
• Remove _source_index from MultiIndex (#9191) @vyasr
• Fix typo in the name of cudf-testing-targets.cmake (#9190) @trxcllnt
• Add support for single-digits in cudf::to_timestamps (#9173) @davidwendt
• Fix cufilejni build include path (#9168) @pxLi
• dask_cudf dispatch registering cleanup (#9160) @galipremsagar
• Remove unneeded stream/mr from a cudf::make_strings_column (#9148) @davidwendt
• Upgrade pandas version in cudf (#9147) @galipremsagar
• make data chunk reader return unique_ptr (#9129) @cwharris
• Add backend for percentile_lookup dispatch (#9118) @galipremsagar
• Refactor implementation of column setitem (#9110) @vyasr
• Fix compile warnings found using nvcc 11.4 (#9101) @davidwendt
• Update to UCX-Py 0.22 (#9099) @pentschev
• Simplify read_avro by removing unnecessary writer/impl classes (#9090) @cwharris
• Allowing %f in format to return nanoseconds (#9081) @marlenezw
• Java bindings for cudf::hash_join (#9080) @jlowe
• Remove stale code in ColumnBase._fill (#9078) @isVoid
• Add support for get_group in GroupBy (#9070) @galipremsagar
• Remove remaining "support" methods from DataFrame (#9068) @vyasr
• Update JNI java CSV APIs to not use deprecated API (#9066) @revans2
• Added method to remove null_masks if the column has no nulls (#9061) @razajafri
• Consolidate Several Series and Dataframe Methods (#9059) @isVoid
• Remove usage of string based set_dtypes for csv & json readers (#9049) @galipremsagar
• Remove some debug print statements from gtests (#9048) @davidwendt
• Support additional format specifiers in from_timestamps (#9047) @davidwendt
• Expose expression base class publicly and simplify public AST API (#9045) @vyasr
• move filepath and mmap logic out of json/csv up to functions.cpp (#9040) @cwharris
• Refactor Index hierarchy (#9039) @vyasr
• cudf now leverages rapids-cmake to reduce CMake boilerplate (#9030) @robertmaynard
• Add support for STRUCT input to groupby (#9024) @mythrocks
• Refactor Frame scans (#9021) @vyasr
• Remove duplicate set_categories code (#9018) @isVoid
• Map support for ParquetWriter (#9013) @razajafri
• Remove aliases of various api.types APIs from utils.dtypes. (#9011) @vyasr
• Java bindings for conditional join output sizes (#9002) @jlowe
• Remove _copy_construct factory (#8999) @vyasr
• ENH Allow arbitrary CMake config options in build.sh (#8996) @dillon-cullinan
• A small optimization for JNI copy column view to column vector (#8985) @revans2
• Fix nvcc warnings in ORC writer (#8975) @devavret
• Support nested structs in rank and dense rank (#8962) @rwlee
• Move compute_column API out of ast namespace (#8957) @vyasr
• Series datetime is_year_end and is_year_start (#8954) @marlenezw
• Make Java AstNode public (#8953) @jlowe
• Replace allocate with device_uvector for subword_tokenize internal tables (#8952) @davidwendt
• cudf.dtype function (#8949) @shwina
• Refactor Frame reductions (#8944) @vyasr
• Add deprecation warning for Series.set_mask API (#8943) @galipremsagar
• Move AST evaluator into a separate header (#8930) @vyasr
• JNI Aggregation Type Changes (#8919) @revans2
• Move template parameter to function parameter in cudf::detail::left_semi_anti_join (#8914) @davidwendt
• Upgrade arrow & pyarrow to 5.0.0 (#8908) @galipremsagar
• Add groupby_aggregation and groupby_scan_aggregation classes and force their usage. (#8906) @nvdbaranec
• Move structs_column_tests.cu to .cpp. (#8902) @mythrocks
• Add stream and memory-resource parameters to struct-scalar copy ctor (#8901) @davidwendt
• Combine linearizer and ast_plan (#8900) @vyasr
• Add Java bindings for conditional join gather maps (#8888) @jlowe
• Remove max version pin for dask & distributed on development branch (#8881) @galipremsagar
• fix cufilejni build w/ c++17 (#8877) @pxLi
• Add struct accessor to dask-cudf (#8874) @NV-jpt
• Migrate dask-cudf CudfEngine to leverage ArrowDatasetEngine (#8871) @rjzamora
• Add JNI for extract_quarter, add_calendrical_months, and is_leap_year (#8863) @revans2
• Change cudf::scalar copy and move constructors to protected (#8857) @davidwendt
• Replace is_same<>::value with is_same_v<> (#8852) @codereport
• Add min pytorch version to importorskip in pytest (#8851) @galipremsagar
• Java bindings for regex replace (#8847) @jlowe
• Remove make strings children with null mask (#8830) @davidwendt
• Refactor conditional joins (#8815) @vyasr
• Small cleanup (unused headers / commented code removals) (#8799) @codereport
• ENH Replace gpuci_conda_retry with gpuci_mamba_retry (#8770) @dillon-cullinan
• Update cudf java bindings to 21.10.0-SNAPSHOT (#8765) @pxLi
• Refactor and improve join benchmarks with nvbench (#8734) @PointKernel
• Refactor Python factories and remove usage of Table for libcudf output handling (#8687) @vyasr
• Optimize URL Decoding (#8622) @gaohao95
• Parquet writer dictionary encoding refactor (#8476) @devavret
• Use nvcomp's snappy decompression in parquet reader (#8252) @devavret
• Use nvcomp's snappy compressor in parquet writer (#8229) @devavret

v21.08.03

v21.08.02

v21.08.01

🚨 Breaking Changes

• Fix a crash in pack() when being handed tables with no columns. (#8697) @nvdbaranec
• Remove unused cudf::strings::create_offsets (#8663) @davidwendt
• Add delimiter parameter to cudf::strings::capitalize() (#8620) @davidwendt
• Change default datetime index resolution to ns to match pandas (#8611) @vyasr
• Add sequence_type parameter to cudf::strings::title function (#8602) @davidwendt
• Add strings::repeat_strings API that can repeat each string a different number of times (#8561) @ttnghia
• String-to-boolean conversion is different from Pandas (#8549) @skirui-source
• Add accurate hash join size functions (#8453) @PointKernel
• Expose a Decimal32Dtype in cuDF Python (#8438) @skirui-source
• Update dask make_meta changes to be compatible with dask upstream (#8426) @galipremsagar
• Adapt cudf::scalar classes to changes in rmm::device_scalar (#8411) @harrism
• Remove special Index class from the general index class hierarchy (#8309) @vyasr
• Add first-class dtype utilities (#8308) @vyasr
• ORC - Support reading multiple orc files/buffers in a single operation (#8142) @jdye64
• Upgrade arrow to 4.0.1 (#7495) @galipremsagar

🐛 Bug Fixes

• Fix contains check in string column (#8834) @galipremsagar
• Remove unused variable from row_bit_count_test. (#8829) @mythrocks
• Fixes issue with null struct columns in ORC reader (#8819) @rgsl888prabhu
• Set CMake vars for python/parquet support in libarrow builds (#8808) @vyasr
• Handle empty child columns in row_bit_count() (#8791) @mythrocks
• Revert "Remove cudf unneeded build time requirement of the cuda driver" (#8784) @robertmaynard
• Fix isort error in utils.pyx (#8771) @charlesbluca
• Handle sliced struct/list columns properly in concatenate() bounds checking. (#8760) @nvdbaranec
• Fix issues with _CPackedColumns.serialize() handling of host and device data (#8759) @charlesbluca
• Fix issues with MultiIndex in dropna, stack & reset_index (#8753) @galipremsagar
• Write pandas extension types to parquet file metadata (#8749) @devavret
• Fix where to handle DataFrame & Series input combination (#8747) @galipremsagar
• Fix replace to handle null values correctly (#8744) @galipremsagar
• Handle sliced structs properly in pack/contiguous_split. (#8739) @nvdbaranec
• Fix issue in slice() where columns with a positive offset were computing null counts incorrectly. (#8738) @nvdbaranec
• Fix cudf.Series constructor to handle list of sequences (#8735) @galipremsagar
• Fix min/max sorted groupby aggregation on string column with nulls (argmin, argmax sentinel value missing on nulls) (#8731) @karthikeyann
• Fix orc reader assert on create data_type in debug (#8706) @davidwendt
• Fix min/max inclusive cudf::scan for strings column (#8705) @davidwendt
• JNI: Fix driver version assertion logic in testGetCudaRuntimeInfo (#8701) @sperlingxx
• Adding fix for skip_rows and crash in orc reader (#8700) @rgsl888prabhu
• Bug fix: replace_nulls_policy functor not returning correct indices for gathermap (#8699) @isVoid
• Fix a crash in pack() when being handed tables with no columns. (#8697) @nvdbaranec
• Add post-processing steps to dask_cudf.groupby.CudfSeriesGroupby.aggregate (#8694) @charlesbluca
• JNI build no longer looks for Arrow in conda environment (#8686) @jlowe
• Handle arbitrarily different data in null list column rows when checking for equivalency. (#8666) @nvdbaranec
• Add ConfigureNVBench to avoid concurrent main() entry points (#8662) @PointKernel
• Pin *arrow to use *cuda in run (#8651) @jakirkham
• Add proper support for tolerances in testing methods. (#8649) @vyasr
• Support multi-char case conversion in capitalize function (#8647) @davidwendt
• Fix repeated mangled names in read_csv with duplicate column names (#8645) @karthikeyann
• Temporarily disable libcudf example build tests (#8642) @isVoid
• Use conda-sourced cudf artifacts for libcudf example in CI (#8638) @isVoid
• Ensure dev environment uses Arrow GPU packages (#8637) @charlesbluca
• Fix bug that columns only initialized once when specified columns and index in dataframe ctor (#8628) @isVoid
• Propagate **kwargs through to as_*_column methods (#8618) @shwina
• Fix orc_reader_benchmark.cpp compile error (#8609) @davidwendt
• Fix missed renumbering of Aggregation values (#8600) @revans2
• Update cmake to 3.20.5 in the Java Docker image (#8593) @NvTimLiu
• Fix bug in replace_with_backrefs when group has greedy quantifier (#8575) @davidwendt
• Apply metadata to keys before returning in Frame._encode (#8560) @charlesbluca
• Fix for strings containing special JSON characters in get_json_object(). (#8556) @nvdbaranec
• Fix debug compile error in gather_struct_tests.cpp (#8554) @davidwendt
• String-to-boolean conversion is different from Pandas (#8549) @skirui-source
• Fix __repr__ output with display.max_rows is None (#8547) @galipremsagar
• Fix size passed to column constructors in _with_type_metadata (#8539) @shwina
• Properly retrieve last column when -1 is specified for column index (#8529) @isVoid
• Fix importing apply from dask (#8517) @galipremsagar
• Fix offset of the string dictionary length stream (#8515) @vuule
• Fix double counting of selected columns in CSV reader (#8508) @ochan1
• Incorrect map size in scatter_to_gather corrupts struct columns (#8507) @gerashegalov
• replace_nulls properly propagates memory resource to gather calls (#8500) @robertmaynard
• Disallow groupby aggs for StructColumns (#8499) @charlesbluca
• Fixes out-of-bounds access for small files in unzip (#8498) @elstehle
• Adding support for writing empty dataframe (#8490) @shaneding
• Fix exclusive scan when including nulls and improve testing (#8478) @harrism
• Add workaround for crash in libcudf debug build using output_indexalator in thrust::lower_bound (#8432) @davidwendt
• Install only the same Thrust files that Thrust itself installs (#8420) @robertmaynard
• Add nightly version for ucx-py in ci script (#8419) @galipremsagar
• Fix null_equality config of rolling_collect_set (#8415) @sperlingxx
• CollectSetAggregation: implement RollingAggregation interface (#8406) @sperlingxx
• Handle pre-sliced nested columns in contiguous_split. (#8391) @nvdbaranec
• Fix bitmask_tests.cpp host accessing device memory (#8370) @davidwendt
• Fix concurrent_unordered_map to prevent accessing padding bits in pair_type (#8348) @davidwendt
• BUG FIX: Raise appropriate strings error when concatenating strings column (#8290) @skirui-source
• Make gpuCI and pre-commit style configurations consistent (#8215) @charlesbluca
• Add collect list to dask-cudf groupby aggregations (#8045) @charlesbluca

📖 Documentation

• Update Python UDFs notebook (#8810) @brandon-b-miller
• Fix dask.dataframe API docs links after reorg (#8772) @jsignell
• Fix instructions for running cuDF/dask-cuDF tests in CONTRIBUTING.md (#8724) @shwina
• Translate Markdown documentation to rST and remove recommonmark (#8698) @vyasr
• Fixed spelling mistakes in libcudf documentation (#8664) @karthikeyann
• Custom Sphinx Extension: PandasCompat (#8643) @isVoid
• Fix README.md (#8535) @ajschmidt8
• Change namespace contains_nulls to struct (#8523) @davidwendt
• Add info about NVTX ranges to dev guide (#8461) @jrhemstad
• Fixed documentation bug in groupby agg method (#8325) @ahmet-uyar

🚀 New Features

• Fix concatenating structs (#8811) @shaneding
• Implement JNI for groupby aggregations M2 and MERGE_M2 (#8763) @ttnghia
• Bump isort to 5.6.4 and remove isort overrides made for 5.0.7 (#8755) @charlesbluca
• Implement __setitem__ for StructColumn (#8737) @shaneding
• Add is_leap_year to DateTimeProperties and DatetimeIndex (#8736) @isVoid
• Add struct.explode() method (#8729) @shwina
• Add DataFrame.to_struct() method to convert a DataFrame to a struct Series (#8728) @shwina
• Add support for list type in ORC writer (#8723) @vuule
• Fix slicing from struct columns and accessing struct columns (#8719) @shaneding
• Add datetime::is_leap_year (#8711) @isVoid
• Accessing struct columns from dask_cudf (#8675) @shaneding
• Added pct_change to Series (#8650) @TravisHester
• Add strings support to cudf::shift function (#8648) @davidwendt
• Support Scatter struct_scalar (#8630) @isVoid
• Struct scalar from host dictionary (#8629) @shaneding
• Add dayofyear and day_of_year to Series, DatetimeColumn, and DatetimeIndex (#8626) @beckernick
• JNI support for capitalize (#8624) @firestarman
• Add delimiter parameter to cudf::strings::capitalize() (#8620) @davidwendt
• Add NVBench in CMake (#8619) @PointKernel
• Change default datetime index resolution to ns to match pandas (#8611) @vyasr
• ListColumn __setitem__ (#8606) @brandon-b-miller
• Implement groupby aggregations M2 and MERGE_M2 (#8605) @ttnghia
• Add sequence_type parameter to cudf::strings::title function (#8602) @davidwendt
• Adding support for list and struct type in ORC Reader (#8599) @rgsl888prabhu
• Benchmark for strings::repeat_strings APIs (#8589) @ttnghia
• Nested scalar support for copy if else (#8588) @gerashegalov
• User specified decimal columns to float64 (#8587) @jdye64
• Add get_element for struct column (#8578) @isVoid
• Python changes for adding __getitem__ for struct (#8577) @shaneding
• Add strings::repeat_strings API that can repeat each string a different number of times (#8561) @ttnghia
• Refactor tests/iterator_utilities.hpp functions (#8540) @ttnghia
• Support MERGE_LISTS and MERGE_SETS in Java package (#8516) @sperlingxx
• Decimal support csv reader (#8511) @elstehle
• Add column type tests (#8505) @isVoid
• Warn when downscaling decimal columns (#8492) @ChrisJar
• Add JNI for strings::repeat_strings (#8491) @ttnghia
• Add Index.get_loc for Numerical, String Index support (#8489) @isVoid
• Expose half_up rounding in cuDF (#8477) @shwina
• Java APIs to fetch CUDA runtime info (#8465) @sperlingxx
• Add str.edit_distance_matrix (#8463) @isVoid
• Support constructing cudf.Scalar objects from host side lists (#8459) @brandon-b-miller
• Add accurate hash join size functions (#8453) @PointKernel
• Add cudf::strings::integer_to_hex convert API (#8450) @davidwendt
• Create objects from iterables that contain cudf.NA (#8442) @brandon-b-miller
• JNI bindings for sort_lists (#8439) @sperlingxx
• Expose a Decimal32Dtype in cuDF Python (#8438) @skirui-source
• Replace all_null() and all_valid() by iterator_all_nulls() and iterator_no_null() in tests (#8437) @ttnghia
• Implement groupby MERGE_LISTS and MERGE_SETS aggregates (#8436) @ttnghia
• Add public libcudf match_dictionaries API (#8429) @davidwendt
• Add move constructors for string_scalar and struct_scalar (#8428) @ttnghia
• Implement strings::repeat_strings (#8423) @ttnghia
• STRUCT column support for cudf::merge. (#8422) @nvdbaranec
• Implement reverse in libcudf (#8410) @shaneding
• Support multiple input files/buffers for read_json (#8403) @jdye64
• Improve test coverage for struct search (#8396) @ttnghia
• Add groupby.fillna (#8362) @isVoid
• Enable AST-based joining (#8214) @vyasr
• Generalized null support in user defined functions (#8213) @brandon-b-miller
• Add compiled binary operation (#8192) @karthikeyann
• Implement .describe() for DataFrameGroupBy (#8179) @skirui-source
• ORC - Support reading multiple orc files/buffers in a single operation (#8142) @jdye64
• Add Python bindings for lists::concatenate_list_elements and expose them as .list.concat() (#8006) @shwina
• Use Arrow URI FileSystem backed instance to retrieve remote files (#7709) @jdye64
• Example to build custom application and link to libcudf (#7671) @isVoid
• Upgrade arrow to 4.0.1 (#7495) @galipremsagar

🛠️ Improvements

• Provide a better error message when CUDA::cuda_driver not found (#8794) @robertmaynard
• Remove anonymous namespace from null_mask.cuh (#8786) @nvdbaranec
• Allow cudf to be built without libcuda.so existing (#8751) @robertmaynard
• Pin mimesis to <4.1 (#8745) @galipremsagar
• Update conda environment name for CI (#8692) @ajschmidt8
• Remove flatbuffers dependency (#8671) @Ethyling
• Add options to build Arrow with Python and Parquet support (#8670) @trxcllnt
• Remove unused cudf::strings::create_offsets (#8663) @davidwendt
• Update GDS lib version to 1.0.0 (#8654) @pxLi
• Support for groupby/scan rank and dense_rank aggregations (#8652) @rwlee
• Fix usage of deprecated arrow ipc API (#8632) @revans2
• Use absolute imports in cudf (#8631) @galipremsagar
• ENH Add Java CI build script (#8627) @dillon-cullinan
• Add DeprecationWarning to ser.str.subword_tokenize (#8603) @VibhuJawa
• Rewrite binary operations for improved performance and additional type support (#8598) @vyasr
• Fix mypy errors surfacing because of numpy-1.21.0 (#8595) @galipremsagar
• Remove unneeded includes from cudf::string_view headers (#8594) @davidwendt
• Use cmake 3.20.1 as it is now required by rmm (#8586) @robertmaynard
• Remove device debug symbols from cmake CUDF_CUDA_FLAGS (#8584) @davidwendt
• Dask-CuDF: use default Dask Dataframe optimizer (#8581) @madsbk
• Remove checking if an unsigned value is less than zero (#8579) @robertmaynard
• Remove strings_count parameter from cudf::strings::detail::create_chars_child_column (#8576) @davidwendt
• Make cudf.api.types imports consistent (#8571) @galipremsagar
• Modernize libcudf basic example CMakeFile; updates CI build tests (#8568) @isVoid
• Rename concatenate_tests.cu to .cpp (#8555) @davidwendt
• enable window lead/lag test on struct (#8548) @wbo4958
• Add Java methods to split and write column views (#8546) @razajafri
• Small cleanup (#8534) @codereport
• Unpin dask version in CI (#8533) @galipremsagar
• Added optional flag for building Arrow with S3 filesystem support (#8531) @jdye64
• Minor clean up of various internal column and frame utilities (#8528) @vyasr
• Rename some copying_test source files .cu to .cpp (#8527) @davidwendt
• Correct the last warnings and issues when using newer cuda versions (#8525) @robertmaynard
• Correct unused parameter warnings in transform and unary ops (#8521) @robertmaynard
• Correct unused parameter warnings in string algorithms (#8509) @robertmaynard
• Add in JNI APIs for scan, replace_nulls, group_by.scan, and group_by.replace_nulls (#8503) @revans2
• Fix 21.08 forward-merge conflicts (#8502) @ajschmidt8
• Fix Cython formatting command in Contributing.md. (#8496) @marlenezw
• Bug/correct unused parameters in reshape and text (#8495) @robertmaynard
• Correct unused parameter warnings in partitioning and stream compact (#8494) @robertmaynard
• Correct unused parameter warnings in labelling and list algorithms (#8493) @robertmaynard
• Refactor index construction (#8485) @vyasr
• Correct unused parameter warnings in replace algorithms (#8483) @robertmaynard
• Correct unused parameter warnings in reduction algorithms (#8481) @robertmaynard
• Correct unused parameter warnings in io algorithms (#8480) @robertmaynard
• Correct unused parameter warnings in interop algorithms (#8479) @robertmaynard
• Correct unused parameter warnings in filling algorithms (#8468) @robertmaynard
• Correct unused parameter warnings in groupby (#8467) @robertmaynard
• use libcu++ time_point as timestamp (#8466) @karthikeyann
• Modify reprog_device::extract to return groups in a single pass (#8460) @davidwendt
• Update minimum Dask requirement to 2021.6.0 (#8458) @pentschev
• Fix failures when performing binary operations on DataFrames with empty columns (#8452) @ChrisJar
• Fix conflicts in 8447 (#8448) @ajschmidt8
• Add serialization methods for List and StructDtype (#8441) @charlesbluca
• Replace make_empty_strings_column with make_empty_column (#8435) @davidwendt
• JNI bindings for get_element (#8433) @revans2
• Update dask make_meta changes to be compatible with dask upstream (#8426) @galipremsagar
• Unpin dask version on CI (#8425) @galipremsagar
• Add benchmark for strings/fixed_point convert APIs (#8417) @davidwendt
• Adapt cudf::scalar classes to changes in rmm::device_scalar (#8411) @harrism
• Add benchmark for strings/integers convert APIs (#8402) @davidwendt
• Enable multi-file partitioning in dask_cudf.read_parquet (#8393) @rjzamora
• Correct unused parameter warnings in rolling algorithms (#8390) @robertmaynard
• Correct unused parameters in column round and search (#8389) @robertmaynard
• Add functionality to apply Dtype metadata to ColumnBase (#8373) @charlesbluca
• Refactor setting stack size in regex code (#8358) @davidwendt
• Update Java bindings to 21.08-SNAPSHOT (#8344) @pxLi
• Replace remaining uses of device_vector (#8343) @harrism
• Statically link libnvcomp into libcudfjni (#8334) @jlowe
• Resolve auto merge conflicts for Branch 21.08 from branch 21.06 (#8329) @galipremsagar
• Minor code refactor for sorted_order (#8326) @wbo4958
• Remove special Index class from the general index class hierarchy (#8309) @vyasr
• Add first-class dtype utilities (#8308) @vyasr
• Add option to link Java bindings with Arrow dynamically (#8307) @jlowe
• Refactor ColumnMethods and its subclasses to remove column argument and require parent argument (#8306) @shwina
• Refactor scatter for list columns (#8255) @isVoid
• Expose pack/unpack API to Python (#8153) @charlesbluca
• Adding cudf.cut method (#8002) @marlenezw
• Optimize string gather performance for large strings (#7980) @gaohao95
• Add peak memory usage tracking to cuIO benchmarks (#7770) @devavret
• Updating Clang Version to 11.0.0 (#6695) @codereport

🚨 Breaking Changes

• Add support for make_meta_obj dispatch in dask-cudf (#8342) @galipremsagar
• Add separator-on-null parameter to strings concatenate APIs (#8282) @davidwendt
• Introduce a common parent class for NumericalColumn and DecimalColumn (#8278) @vyasr
• Update ORC statistics API to use C++17 standard library (#8241) @vuule
• Preserve column hierarchy when getting NULL row from LIST column (#8206) @isVoid
• Groupby.shift c++ API refactor and python binding (#8131) @isVoid

🐛 Bug Fixes

• Fix struct flattening to add a validity column only when the input column has null element (#8374) @ttnghia
• Compilation fix: Remove redefinition for std::is_same_v() (#8369) @mythrocks
• Add backward compatibility for dask-cudf to work with other versions of dask (#8368) @galipremsagar
• Handle empty results with nested types in copy_if_else (#8359) @nvdbaranec
• Handle nested column types properly for empty parquet files. (#8350) @nvdbaranec
• Raise error when unsupported arguments are passed to dask_cudf.DataFrame.sort_values (#8349) @galipremsagar
• Raise NotImplementedError for axis=1 in rank (#8347) @galipremsagar
• Add support for make_meta_obj dispatch in dask-cudf (#8342) @galipremsagar
• Update Java string concatenate test for single column (#8330) @tgravescs
• Use empty_like in scatter (#8314) @revans2
• Fix concatenate_lists_ignore_null on rows of all_nulls (#8312) @sperlingxx
• Add separator-on-null parameter to strings concatenate APIs (#8282) @davidwendt
• COLLECT_LIST support returning empty output columns. (#8279) @mythrocks
• Update io util to convert path like object to string (#8275) @ayushdg
• Fix result column types for empty inputs to rolling window (#8274) @mythrocks
• Actually test equality in assert_groupby_results_equal (#8272) @shwina
• CMake always explicitly specify a source files extension (#8270) @robertmaynard
• Fix struct binary search and struct flattening (#8268) @ttnghia
• Revert "patch thrust to fix intmax num elements limitation in scan_by_key" (#8263) @cwharris
• upgrade dlpack to 0.5 (#8262) @cwharris
• Fixes CSV-reader type inference for thousands separator and decimal point (#8261) @elstehle
• Fix incorrect assertion in Java concat (#8258) @sperlingxx
• Copy nested types upon construction (#8244) @isVoid
• Preserve column hierarchy when getting NULL row from LIST column (#8206) @isVoid
• Clip decimal binary op precision at max precision (#8194) @ChrisJar

📖 Documentation

• Add docstring for dask_cudf.read_csv (#8355) @galipremsagar
• Fix cudf release version in readme (#8331) @galipremsagar
• Fix structs column description in dev docs (#8318) @isVoid
• Update readme with correct CUDA versions (#8315) @raydouglass
• Add description of the cuIO GDS integration (#8293) @vuule
• Remove unused parameter from copy_partition kernel documentation (#8283) @robertmaynard

🚀 New Features

• Add support merging b/w categorical data (#8332) @galipremsagar
• Java: Support struct scalar (#8327) @sperlingxx
• added _is_homogeneous property (#8299) @shaneding
• Added decimal writing for CSV writer (#8296) @kaatish
• Java: Support creating a scalar from utf8 string (#8294) @firestarman
• Add Java API for Concatenate strings with separator (#8289) @tgravescs
• strings::join_list_elements options for empty list inputs (#8285) @ttnghia
• Return python lists for getitem calls to list type series (#8265) @brandon-b-miller
• add unit tests for lead/lag on list for row window (#8259) @wbo4958
• Create a String column from UTF8 String byte arrays (#8257) @firestarman
• Support scattering list_scalar (#8256) @isVoid
• Implement lists::concatenate_list_elements (#8231) @ttnghia
• Support for struct scalars. (#8220) @nvdbaranec
• Add support for decimal types in ORC writer (#8198) @vuule
• Support create lists column from a list_scalar (#8185) @isVoid
• Groupby.shift c++ API refactor and python binding (#8131) @isVoid
• Add groupby::replace_nulls(replace_policy) api (#7118) @isVoid

🛠️ Improvements

• Support Dask + Distributed 2021.05.1 (#8392) @jakirkham
• Add aliases for string methods (#8353) @shwina
• Update environment variable used to determine cuda_version (#8321) @ajschmidt8
• JNI: Refactor the code of making column from scalar (#8310) @firestarman
• Update CHANGELOG.md links for calver (#8303) @ajschmidt8
• Merge branch-0.19 into branch-21.06 (#8302) @ajschmidt8
• use address and length for GDS reads/writes (#8301) @rongou
• Update cudfjni version to 21.06.0 (#8292) @pxLi
• Update docs build script (#8284) @ajschmidt8
• Make device_buffer streams explicit and enforce move construction (#8280) @harrism
• Introduce a common parent class for NumericalColumn and DecimalColumn (#8278) @vyasr
• Do not add nulls to the hash table when null_equality::NOT_EQUAL is passed to left_semi_join and left_anti_join (#8277) @nvdbaranec
• Enable implicit casting when concatenating mixed types (#8276) @ChrisJar
• Fix CMake FindPackage rmm, pin dev envs' dlpack to v0.3 (#8271) @trxcllnt
• Update cudfjni version to 21.06 (#8267) @pxLi
• support RMM aligned resource adapter in JNI (#8266) @rongou
• Pass compiler environment variables to conda python build (#8260) @Ethyling
• Remove abc inheritance from Serializable (#8254) @vyasr
• Move more methods into SingleColumnFrame (#8253) @vyasr
• Update ORC statistics API to use C++17 standard library (#8241) @vuule
• Correct unused parameter warnings in dictonary algorithms (#8239) @robertmaynard
• Correct unused parameters in the copying algorithms (#8232) @robertmaynard
• IO statistics cleanup (#8191) @kaatish
• Refactor of rolling_window implementation. (#8158) @nvdbaranec
• Add a flag for allowing single quotes in JSON strings. (#8144) @nvdbaranec
• Column refactoring 2 (#8130) @vyasr
• support space in workspace (#7956) @jolorunyomi
• Support collect_set on rolling window (#7881) @sperlingxx

🚨 Breaking Changes

• Allow hash_partition to take a seed value (#7771) @magnatelee
• Allow merging index column with data column using keyword "on" (#7736) @skirui-source
• Change JNI API to avoid loading native dependencies when creating sort order classes. (#7729) @revans2
• Replace device_vector with device_uvector in null_mask (#7715) @harrism
• Don't identify decimals as strings. (#7710) @vyasr
• Fix Java Parquet write after writer API changes (#7655) @revans2
• Convert cudf::concatenate APIs to use spans and device_uvector (#7621) @harrism
• Update missing docstring examples in python public APIs (#7546) @galipremsagar
• Remove unneeded step parameter from strings::detail::copy_slice (#7525) @davidwendt
• Rename ARROW_STATIC_LIB because it conflicts with one in FindArrow.cmake (#7518) @trxcllnt
• Match Pandas logic for comparing two objects with nulls (#7490) @brandon-b-miller
• Add struct support to parquet writer (#7461) @devavret
• Join APIs that return gathermaps (#7454) @shwina
• fixed_point + cudf::binary_operation API Changes (#7435) @codereport
• Fix BUG: Exception when PYTHONOPTIMIZE=2 (#7434) @skirui-source
• Change nvtext::load_vocabulary_file to return a unique ptr (#7424) @davidwendt
• Refactor strings column factories (#7397) @harrism
• Use CMAKE_CUDA_ARCHITECTURES (#7391) @robertmaynard
• Upgrade pandas to 1.2 (#7375) @galipremsagar
• Rename logical_cast to bit_cast and allow additional conversions (#7373) @ttnghia
• Rework libcudf CMakeLists.txt to export targets for CPM (#7107) @trxcllnt

🐛 Bug Fixes

• unsnap: busy wait a number of cycles (#8073) @vuule
• Fix returned column type when extracting from an empty list column (#8031) @jlowe
• Don't reindex an new value on setitem if the original dataframe was empty (#8026) @vyasr
• Fix a NameError in meta dispatch API (#7996) @galipremsagar
• Reindex in DataFrame.__setitem__ (#7957) @galipremsagar
• jitify direct-to-cubin compilation and caching. (#7919) @cwharris
• Use dynamic cudart for nvcomp in java build (#7896) @abellina
• fix "incompatible redefinition" warnings (#7894) @cwharris
• cudf consistently specifies the cuda runtime (#7887) @robertmaynard
• disable verbose output for jitify_preprocess (#7886) @cwharris
• CMake jit_preprocess_files function only runs when needed (#7872) @robertmaynard
• Push DeviceScalar construction into cython for list.contains (#7864) @brandon-b-miller
• cudf now sets an install rpath of $ORIGIN (#7863) @robertmaynard
• Don't install Thrust examples, tests, docs, and python files (#7811) @robertmaynard
• Sort by index in groupby tests more consistently (#7802) @shwina
• Revert "Update conda recipes pinning of repo dependencies (#7743)" (#7793) @raydouglass
• Add decimal column handling in copy_type_metadata (#7788) @shwina
• Add column names validation in parquet writer (#7786) @galipremsagar
• Fix Java explode outer unit tests (#7782) @jlowe
• Fix compiler warning about non-POD types passed through ellipsis (#7781) @jrhemstad
• User resource fix for replace_nulls (#7769) @magnatelee
• Fix type dispatch for columnar replace_nulls (#7768) @jlowe
• Add ignore_order parameter to dask-cudf concat dispatch (#7765) @galipremsagar
• Fix slicing and arrow representations of decimal columns (#7755) @vyasr
• Fixing issue with explode_outer position not nulling position entries of null rows (#7754) @hyperbolic2346
• Implement scatter for struct columns (#7752) @ttnghia
• Fix data corruption in string columns (#7746) @galipremsagar
• Fix string length in stripe dictionary building (#7744) @kaatish
• Update conda recipes pinning of repo dependencies (#7743) @mike-wendt
• Enable dask dispatch to cuDF's is_categorical_dtype for cuDF objects (#7740) @brandon-b-miller
• Fix dictionary size computation in ORC writer (#7737) @vuule
• Fix cudf::cast overflow for decimal64 to int32_t or smaller in certain cases (#7733) @codereport
• Change JNI API to avoid loading native dependencies when creating sort order classes. (#7729) @revans2
• Disable column_view data accessors for unsupported types (#7725) @jrhemstad
• Materialize RangeIndex when index=True in parquet writer (#7711) @galipremsagar
• Don't identify decimals as strings. (#7710) @vyasr
• Fix return type of DataFrame.argsort (#7706) @galipremsagar
• Fix/correct cudf installed package requirements (#7688) @robertmaynard
• Fix SparkMurmurHash3_32 hash inconsistencies with Apache Spark (#7672) @jlowe
• Fix ORC reader issue with reading empty string columns (#7656) @rgsl888prabhu
• Fix Java Parquet write after writer API changes (#7655) @revans2
• Fixing empty null lists throwing explode_outer for a loop. (#7649) @hyperbolic2346
• Fix internal compiler error during JNI Docker build (#7645) @jlowe
• Fix Debug build break with device_uvectors in grouped_rolling.cu (#7633) @mythrocks
• Parquet reader: Fix issue when using skip_rows on non-nested columns containing nulls (#7627) @nvdbaranec
• Fix ORC reader for empty DataFrame/Table (#7624) @rgsl888prabhu
• Fix specifying GPU architecture in JNI build (#7612) @jlowe
• Fix ORC writer OOM issue (#7605) @vuule
• Fix 0.18 --> 0.19 automerge (#7589) @kkraus14
• Fix ORC issue with incorrect timestamp nanosecond values (#7581) @vuule
• Fix missing Dask imports (#7580) @kkraus14
• CMAKE_CUDA_ARCHITECTURES doesn't change when build-system invokes cmake (#7579) @robertmaynard
• Another fix for offsets_end() iterator in lists_column_view (#7575) @ttnghia
• Fix ORC writer output corruption with string columns (#7565) @vuule
• Fix cudf::lists::sort_lists failing for sliced column (#7564) @ttnghia
• FIX Fix Anaconda upload args (#7558) @dillon-cullinan
• Fix index mismatch issue in equality related APIs (#7555) @galipremsagar
• FIX Revert gpuci_conda_retry on conda file output locations (#7552) @dillon-cullinan
• Fix offset_end iterator for lists_column_view, which was not correctl… (#7551) @ttnghia
• Fix no such file dlpack.h error when build libcudf (#7549) @chenrui17
• Update missing docstring examples in python public APIs (#7546) @galipremsagar
• Decimal32 Build Fix (#7544) @razajafri
• FIX Retry conda output location (#7540) @dillon-cullinan
• fix missing renames of dask git branches from master to main (#7535) @kkraus14
• Remove detail from device_span (#7533) @rwlee
• Change dask and distributed branch to main (#7532) @dantegd
• Update JNI build to use CUDF_USE_ARROW_STATIC (#7526) @jlowe
• Make sure rmm::rmm CMake target is visibile to cudf users (#7524) @robertmaynard
• Fix contiguous_split not properly handling output partitions > 2 GB. (#7515) @nvdbaranec
• Change jit launch to safe_launch (#7510) @devavret
• Fix comparison between Datetime/Timedelta columns and NULL scalars (#7504) @brandon-b-miller
• Fix off-by-one error in char-parallel string scalar replace (#7502) @jlowe
• Fix JNI deprecation of all, put it on the wrong version before (#7501) @revans2
• Fix Series/Dataframe Mixed Arithmetic (#7491) @brandon-b-miller
• Fix JNI build after removal of libcudf sub-libraries (#7486) @jlowe
• Correctly compile benchmarks (#7485) @robertmaynard
• Fix bool column corruption with ORC Reader (#7483) @rgsl888prabhu
• Fix __repr__ for categorical dtype (#7476) @galipremsagar
• Java cleaner synchronization (#7474) @abellina
• Fix java float/double parsing tests (#7473) @revans2
• Pass stream and user resource to make_default_constructed_scalar (#7469) @magnatelee
• Improve stability of dask_cudf.DataFrame.var and dask_cudf.DataFrame.std (#7453) @rjzamora
• Missing device_storage_dispatch change affecting cudf::gather (#7449) @codereport
• fix cuFile JNI compile errors (#7445) @rongou
• Support Series.__setitem__ with key to a new row (#7443) @isVoid
• Fix BUG: Exception when PYTHONOPTIMIZE=2 (#7434) @skirui-source
• Make inclusive scan safe for cases with leading nulls (#7432) @magnatelee
• Fix typo in list_device_view::pair_rep_end() (#7423) @mythrocks
• Fix string to double conversion and row equivalent comparison (#7410) @ttnghia
• Fix thrust failure when transfering data from device_vector to host_vector with vectors of size 1 (#7382) @ttnghia
• Fix std::exeception catch-by-reference gcc9 compile error (#7380) @davidwendt
• Fix skiprows issue with ORC Reader (#7359) @rgsl888prabhu
• fix Arrow CMake file (#7358) @rongou
• Fix lists::contains() for NaN and Decimals (#7349) @mythrocks
• Handle cupy array in Dataframe.__setitem__ (#7340) @galipremsagar
• Fix invalid-device-fn error in cudf::strings::replace_re with multiple regex's (#7336) @davidwendt
• FIX Add codecov upload block to gpu script (#6860) @dillon-cullinan

📖 Documentation

• Fix join API doxygen (#7890) @shwina
• Add Resources to README. (#7697) @bdice
• Add isin examples in Docstring (#7479) @galipremsagar
• Resolving unlinked type shorthands in cudf doc (#7416) @isVoid
• Fix typo in regex.md doc page (#7363) @davidwendt
• Fix incorrect strings_column_view::chars_size documentation (#7360) @jlowe

🚀 New Features

• Enable basic reductions for decimal columns (#7776) @ChrisJar
• Enable join on decimal columns (#7764) @ChrisJar
• Allow merging index column with data column using keyword "on" (#7736) @skirui-source
• Implement DecimalColumn + Scalar and add cudf.Scalars of Decimal64Dtype (#7732) @brandon-b-miller
• Add support for unique groupby aggregation (#7726) @shwina
• Expose libcudf's label_bins function to cudf (#7724) @vyasr
• Adding support for equi-join on struct (#7720) @hyperbolic2346
• Add decimal column comparison operations (#7716) @isVoid
• Implement scan operations for decimal columns (#7707) @ChrisJar
• Enable typecasting between decimal and int (#7691) @ChrisJar
• Enable decimal support in parquet writer (#7673) @devavret
• Adds list.unique API (#7664) @isVoid
• Fix NaN handling in drop_list_duplicates (#7662) @ttnghia
• Add lists.sort_values API (#7657) @isVoid
• Add is_integer API that can check for the validity of a string-to-integer conversion (#7642) @ttnghia
• Adds explode API (#7607) @isVoid
• Adds list.take, python binding for cudf::lists::segmented_gather (#7591) @isVoid
• Implement cudf::label_bins() (#7554) @vyasr
• Add Python bindings for lists::contains (#7547) @skirui-source
• cudf::row_bit_count() support. (#7534) @nvdbaranec
• Implement drop_list_duplicates (#7528) @ttnghia
• Add Python bindings for lists::extract_lists_element (#7505) @skirui-source
• Add explode_outer and explode_outer_position (#7499) @hyperbolic2346
• Match Pandas logic for comparing two objects with nulls (#7490) @brandon-b-miller
• Add struct support to parquet writer (#7461) @devavret
• Enable type conversion from float to decimal type (#7450) @ChrisJar
• Add cython for converting strings/fixed-point functions (#7429) @davidwendt
• Add struct column support to cudf::sort and cudf::sorted_order (#7422) @karthikeyann
• Implement groupby collect_set (#7420) @ttnghia
• Merge branch-0.18 into branch-0.19 (#7411) @raydouglass
• Refactor strings column factories (#7397) @harrism
• Add groupby scan operations (sort groupby) (#7387) @karthikeyann
• Add cudf::explode_position (#7376) @hyperbolic2346
• Add string conversion to/from decimal values libcudf APIs (#7364) @davidwendt
• Add groupby SUM_OF_SQUARES support (#7362) @karthikeyann
• Add Series.drop api (#7304) @isVoid
• get_json_object() implementation (#7286) @nvdbaranec
• Python API for LIstMethods.len() (#7283) @isVoid
• Support null_policy::EXCLUDE for COLLECT rolling aggregation (#7264) @mythrocks
• Add support for special tokens in nvtext::subword_tokenizer (#7254) @davidwendt
• Fix inplace update of data and add Series.update (#7201) @galipremsagar
• Implement cudf::group_by (hash) for decimal32 and decimal64 (#7190) @codereport
• Adding support to specify "level" parameter for Dataframe.rename (#7135) @skirui-source

🛠️ Improvements

• fix GDS include path for version 0.95 (#7877) @rongou
• Update dask + distributed to 2021.4.0 (#7858) @jakirkham
• Add ability to extract include dirs from CUDF_HOME (#7848) @galipremsagar
• Add USE_GDS as an option in build script (#7833) @pxLi
• add an allocate method with stream in java DeviceMemoryBuffer (#7826) @rongou
• Constrain dask and distributed versions to 2021.3.1 (#7825) @shwina
• Revert dask versioning of concat dispatch (#7823) @galipremsagar
• add copy methods in Java memory buffer (#7791) @rongou
• Update README and CONTRIBUTING for 0.19 (#7778) @robertmaynard
• Allow hash_partition to take a seed value (#7771) @magnatelee
• Turn on NVTX by default in java build (#7761) @tgravescs
• Add Java bindings to join gather map APIs (#7751) @jlowe
• Add replacements column support for Java replaceNulls (#7750) @jlowe
• Add Java bindings for row_bit_count (#7749) @jlowe
• Remove unused JVM array creation (#7748) @jlowe
• Added JNI support for new is_integer (#7739) @revans2
• Create and promote library aliases in libcudf installations (#7734) @trxcllnt
• Support groupby operations for decimal dtypes (#7731) @vyasr
• Memory map the input file only when GDS compatiblity mode is not used (#7717) @vuule
• Replace device_vector with device_uvector in null_mask (#7715) @harrism
• Struct hashing support for SerialMurmur3 and SparkMurmur3 (#7714) @jlowe
• Add gbenchmark for nvtext replace-tokens function (#7708) @davidwendt
• Use stream in groupby calls (#7705) @karthikeyann
• Update codeowners file (#7701) @ajschmidt8
• Cleanup groupby to use host_span, device_span, device_uvector (#7698) @karthikeyann
• Add gbenchmark for nvtext ngrams functions (#7693) @davidwendt
• Misc Python/Cython optimizations (#7686) @shwina
• Add gbenchmark for nvtext tokenize functions (#7684) @davidwendt
• Add column_device_view to orc writer (#7676) @kaatish
• cudf_kafka now uses cuDF CMake export targets (CPM) (#7674) @robertmaynard
• Add gbenchmark for nvtext normalize functions (#7668) @davidwendt
• Resolve unnecessary import of thrust/optional.hpp in types.hpp (#7667) @vyasr
• Feature/optimize accessor copy (#7660) @vyasr
• Fix find_package(cudf) (#7658) @trxcllnt
• Work-around for gcc7 compile error on Centos7 (#7652) @davidwendt
• Add in JNI support for count_elements (#7651) @revans2
• Fix issues with building cudf in a non-conda environment (#7647) @galipremsagar
• Refactor ConfigureCUDA to not conditionally insert compiler flags (#7643) @robertmaynard
• Add gbenchmark for converting strings to/from timestamps (#7641) @davidwendt
• Handle constructing a cudf.Scalar from a cudf.Scalar (#7639) @shwina
• Add in JNI support for table partition (#7637) @revans2
• Add explicit fixed_point merge test (#7635) @codereport
• Add JNI support for IDENTITY hash partitioning (#7626) @revans2
• Java support on explode_outer (#7625) @sperlingxx
• Java support of casting string from/to decimal (#7623) @sperlingxx
• Convert cudf::concatenate APIs to use spans and device_uvector (#7621) @harrism
• Add gbenchmark for cudf::strings::translate function (#7617) @davidwendt
• Use file(COPY ) over file(INSTALL ) so cmake output is reduced (#7616) @robertmaynard
• Use rmm::device_uvector in place of rmm::device_vector for ORC reader/writer and cudf::io::column_buffer (#7614) @vuule
• Refactor Java host-side buffer concatenation to expose separate steps (#7610) @jlowe
• Add gbenchmarks for string substrings functions (#7603) @davidwendt
• Refactor string conversion check (#7599) @ttnghia
• JNI: Pass names of children struct columns to native Arrow IPC writer (#7598) @firestarman
• Revert "ENH Fix stale GHA and prevent duplicates " (#7595) @mike-wendt
• ENH Fix stale GHA and prevent duplicates (#7594) @mike-wendt
• Fix auto-detecting GPU architectures (#7593) @trxcllnt
• Reduce cudf library size (#7583) @robertmaynard
• Optimize cudf::make_strings_column for long strings (#7576) @davidwendt
• Always build and export the cudf::cudftestutil target (#7574) @trxcllnt
• Eliminate literal parameters to uvector::set_element_async and device_scalar::set_value (#7563) @harrism
• Add gbenchmark for strings::concatenate (#7560) @davidwendt
• Update Changelog Link (#7550) @ajschmidt8
• Add gbenchmarks for strings replace regex functions (#7541) @davidwendt
• Add __repr__ for Column and ColumnAccessor (#7531) @shwina
• Support Decimal DIV changes in cudf (#7527) @razajafri
• Remove unneeded step parameter from strings::detail::copy_slice (#7525) @davidwendt
• Use device_uvector, device_span in sort groupby (#7523) @karthikeyann
• Add gbenchmarks for strings extract function (#7522) @davidwendt
• Rename ARROW_STATIC_LIB because it conflicts with one in FindArrow.cmake (#7518) @trxcllnt
• Reduce compile time/size for scan.cu (#7516) @davidwendt
• Change device_vector to device_uvector in nvtext source files (#7512) @davidwendt
• Removed unneeded includes from traits.hpp (#7509) @davidwendt
• FIX Remove random build directory generation for ccache (#7508) @dillon-cullinan
• xfail failing pytest in pandas 1.2.3 (#7507) @galipremsagar
• JNI bit cast (#7493) @revans2
• Combine rolling window function tests (#7480) @mythrocks
• Prepare Changelog for Automation (#7477) @ajschmidt8
• Java support for explode position (#7471) @sperlingxx
• Update 0.18 changelog entry (#7463) @ajschmidt8
• JNI: Support skipping nulls for collect aggregation (#7457) @firestarman
• Join APIs that return gathermaps (#7454) @shwina
• Remove dependence on managed memory for multimap test (#7451) @jrhemstad
• Use cuFile for Parquet IO when available (#7444) @vuule
• Statistics cleanup (#7439) @kaatish
• Add gbenchmarks for strings filter functions (#7438) @davidwendt
• fixed_point + cudf::binary_operation API Changes (#7435) @codereport
• Improve string gather performance (#7433) @jlowe
• Don't use user resource for a temporary allocation in sort_by_key (#7431) @magnatelee
• Detail APIs for datetime functions (#7430) @magnatelee
• Replace thrust::max_element with thrust::reduce in strings findall_re (#7428) @davidwendt
• Add gbenchmark for strings split/split_record functions (#7427) @davidwendt
• Update JNI build to use CMAKE_CUDA_ARCHITECTURES (#7425) @jlowe
• Change nvtext::load_vocabulary_file to return a unique ptr (#7424) @davidwendt
• Simplify type dispatch with device_storage_dispatch (#7419) @codereport
• Java support for casting of nested child columns (#7417) @razajafri
• Improve scalar string replace performance for long strings (#7415) @jlowe
• Remove unneeded temporary device vector for strings scatter specialization (#7409) @davidwendt
• bitmask_or implementation with bitmask refactor (#7406) @rwlee
• Add other cudf::strings::replace functions to current strings replace gbenchmark (#7403) @davidwendt
• Clean up included headers in device_operators.cuh (#7401) @codereport
• Move nullable index iterator to indexalator factory (#7399) @davidwendt
• ENH Pass ccache variables to conda recipe & use Ninja in CI (#7398) @Ethyling
• upgrade maven-antrun-plugin to support maven parallel builds (#7393) @rongou
• Add gbenchmark for strings find/contains functions (#7392) @davidwendt
• Use CMAKE_CUDA_ARCHITECTURES (#7391) @robertmaynard
• Refactor libcudf strings::replace to use make_strings_children utility (#7384) @davidwendt
• Added in JNI support for out of core sort algorithm (#7381) @revans2
• Upgrade pandas to 1.2 (#7375) @galipremsagar
• Rename logical_cast to bit_cast and allow additional conversions (#7373) @ttnghia
• jitify 2 support (#7372) @cwharris
• compile_udf: Cache PTX for similar functions (#7371) @gmarkall
• Add string scalar replace benchmark (#7369) @jlowe
• Add gbenchmark for strings contains_re/count_re functions (#7366) @davidwendt
• Update orc reader and writer fuzz tests (#7357) @galipremsagar
• Improve url_decode performance for long strings (#7353) @jlowe
• cudf::ast Small Refactorings (#7352) @codereport
• Remove std::cout and print in the scatter test function EmptyListsOfNullableStrings. (#7342) @ttnghia
• Use cudf::detail::make_counting_transform_iterator (#7338) @codereport
• Change block size parameter from a global to a template param. (#7333) @nvdbaranec
• Partial clean up of ORC writer (#7324) @vuule
• Add gbenchmark for cudf::strings::to_lower (#7316) @davidwendt
• Update Java bindings version to 0.19-SNAPSHOT (#7307) @pxLi
• Move cudf::test::make_counting_transform_iterator to cudf/detail/iterator.cuh (#7306) @codereport
• Use string literals in fixed_point release_asserts (#7303) @codereport
• Fix merge conflicts for #7295 (#7297) @ajschmidt8
• Add UTF-8 chars to create_random_column<string_view> benchmark utility (#7292) @davidwendt
• Abstracting block reduce and block scan from cuIO kernels with cub apis (#7278) @rgsl888prabhu
• Build.sh use cmake --build to drive build system invocation (#7270) @robertmaynard
• Refactor dictionary support for reductions any/all (#7242) @davidwendt
• Replace stream.value() with stream for stream_view args (#7236) @karthikeyann
• Interval index and interval_range (#7182) @marlenezw
• avro reader integration tests (#7156) @cwharris
• Rework libcudf CMakeLists.txt to export targets for CPM (#7107) @trxcllnt
• Adding Interval Dtype (#6984) @marlenezw
• Cleaning up for loops with make_(counting_)transform_iterator (#6546) @codereport

🚨 Breaking Changes

• Allow hash_partition to take a seed value (#7771) @magnatelee
• Allow merging index column with data column using keyword "on" (#7736) @skirui-source
• Change JNI API to avoid loading native dependencies when creating sort order classes. (#7729) @revans2
• Replace device_vector with device_uvector in null_mask (#7715) @harrism
• Don't identify decimals as strings. (#7710) @vyasr
• Fix Java Parquet write after writer API changes (#7655) @revans2
• Convert cudf::concatenate APIs to use spans and device_uvector (#7621) @harrism
• Update missing docstring examples in python public APIs (#7546) @galipremsagar
• Remove unneeded step parameter from strings::detail::copy_slice (#7525) @davidwendt
• Rename ARROW_STATIC_LIB because it conflicts with one in FindArrow.cmake (#7518) @trxcllnt
• Match Pandas logic for comparing two objects with nulls (#7490) @brandon-b-miller
• Add struct support to parquet writer (#7461) @devavret
• Join APIs that return gathermaps (#7454) @shwina
• fixed_point + cudf::binary_operation API Changes (#7435) @codereport
• Fix BUG: Exception when PYTHONOPTIMIZE=2 (#7434) @skirui-source
• Change nvtext::load_vocabulary_file to return a unique ptr (#7424) @davidwendt
• Refactor strings column factories (#7397) @harrism
• Use CMAKE_CUDA_ARCHITECTURES (#7391) @robertmaynard
• Upgrade pandas to 1.2 (#7375) @galipremsagar
• Rename logical_cast to bit_cast and allow additional conversions (#7373) @ttnghia
• Rework libcudf CMakeLists.txt to export targets for CPM (#7107) @trxcllnt

🐛 Bug Fixes

• Fix returned column type when extracting from an empty list column (#8031) @jlowe
• Don't reindex an new value on setitem if the original dataframe was empty (#8026) @vyasr
• Fix a NameError in meta dispatch API (#7996) @galipremsagar
• Reindex in DataFrame.__setitem__ (#7957) @galipremsagar
• jitify direct-to-cubin compilation and caching. (#7919) @cwharris
• Use dynamic cudart for nvcomp in java build (#7896) @abellina
• fix "incompatible redefinition" warnings (#7894) @cwharris
• cudf consistently specifies the cuda runtime (#7887) @robertmaynard
• disable verbose output for jitify_preprocess (#7886) @cwharris
• CMake jit_preprocess_files function only runs when needed (#7872) @robertmaynard
• Push DeviceScalar construction into cython for list.contains (#7864) @brandon-b-miller
• cudf now sets an install rpath of $ORIGIN (#7863) @robertmaynard
• Don't install Thrust examples, tests, docs, and python files (#7811) @robertmaynard
• Sort by index in groupby tests more consistently (#7802) @shwina
• Revert "Update conda recipes pinning of repo dependencies (#7743)" (#7793) @raydouglass
• Add decimal column handling in copy_type_metadata (#7788) @shwina
• Add column names validation in parquet writer (#7786) @galipremsagar
• Fix Java explode outer unit tests (#7782) @jlowe
• Fix compiler warning about non-POD types passed through ellipsis (#7781) @jrhemstad
• User resource fix for replace_nulls (#7769) @magnatelee
• Fix type dispatch for columnar replace_nulls (#7768) @jlowe
• Add ignore_order parameter to dask-cudf concat dispatch (#7765) @galipremsagar
• Fix slicing and arrow representations of decimal columns (#7755) @vyasr
• Fixing issue with explode_outer position not nulling position entries of null rows (#7754) @hyperbolic2346
• Implement scatter for struct columns (#7752) @ttnghia
• Fix data corruption in string columns (#7746) @galipremsagar
• Fix string length in stripe dictionary building (#7744) @kaatish
• Update conda recipes pinning of repo dependencies (#7743) @mike-wendt
• Enable dask dispatch to cuDF's is_categorical_dtype for cuDF objects (#7740) @brandon-b-miller
• Fix dictionary size computation in ORC writer (#7737) @vuule
• Fix cudf::cast overflow for decimal64 to int32_t or smaller in certain cases (#7733) @codereport
• Change JNI API to avoid loading native dependencies when creating sort order classes. (#7729) @revans2
• Disable column_view data accessors for unsupported types (#7725) @jrhemstad
• Materialize RangeIndex when index=True in parquet writer (#7711) @galipremsagar
• Don't identify decimals as strings. (#7710) @vyasr
• Fix return type of DataFrame.argsort (#7706) @galipremsagar
• Fix/correct cudf installed package requirements (#7688) @robertmaynard
• Fix SparkMurmurHash3_32 hash inconsistencies with Apache Spark (#7672) @jlowe
• Fix ORC reader issue with reading empty string columns (#7656) @rgsl888prabhu
• Fix Java Parquet write after writer API changes (#7655) @revans2
• Fixing empty null lists throwing explode_outer for a loop. (#7649) @hyperbolic2346
• Fix internal compiler error during JNI Docker build (#7645) @jlowe
• Fix Debug build break with device_uvectors in grouped_rolling.cu (#7633) @mythrocks
• Parquet reader: Fix issue when using skip_rows on non-nested columns containing nulls (#7627) @nvdbaranec
• Fix ORC reader for empty DataFrame/Table (#7624) @rgsl888prabhu
• Fix specifying GPU architecture in JNI build (#7612) @jlowe
• Fix ORC writer OOM issue (#7605) @vuule
• Fix 0.18 --> 0.19 automerge (#7589) @kkraus14
• Fix ORC issue with incorrect timestamp nanosecond values (#7581) @vuule
• Fix missing Dask imports (#7580) @kkraus14
• CMAKE_CUDA_ARCHITECTURES doesn't change when build-system invokes cmake (#7579) @robertmaynard
• Another fix for offsets_end() iterator in lists_column_view (#7575) @ttnghia
• Fix ORC writer output corruption with string columns (#7565) @vuule
• Fix cudf::lists::sort_lists failing for sliced column (#7564) @ttnghia
• FIX Fix Anaconda upload args (#7558) @dillon-cullinan
• Fix index mismatch issue in equality related APIs (#7555) @galipremsagar
• FIX Revert gpuci_conda_retry on conda file output locations (#7552) @dillon-cullinan
• Fix offset_end iterator for lists_column_view, which was not correctl… (#7551) @ttnghia
• Fix no such file dlpack.h error when build libcudf (#7549) @chenrui17
• Update missing docstring examples in python public APIs (#7546) @galipremsagar
• Decimal32 Build Fix (#7544) @razajafri
• FIX Retry conda output location (#7540) @dillon-cullinan
• fix missing renames of dask git branches from master to main (#7535) @kkraus14
• Remove detail from device_span (#7533) @rwlee
• Change dask and distributed branch to main (#7532) @dantegd
• Update JNI build to use CUDF_USE_ARROW_STATIC (#7526) @jlowe
• Make sure rmm::rmm CMake target is visibile to cudf users (#7524) @robertmaynard
• Fix contiguous_split not properly handling output partitions > 2 GB. (#7515) @nvdbaranec
• Change jit launch to safe_launch (#7510) @devavret
• Fix comparison between Datetime/Timedelta columns and NULL scalars (#7504) @brandon-b-miller
• Fix off-by-one error in char-parallel string scalar replace (#7502) @jlowe
• Fix JNI deprecation of all, put it on the wrong version before (#7501) @revans2
• Fix Series/Dataframe Mixed Arithmetic (#7491) @brandon-b-miller
• Fix JNI build after removal of libcudf sub-libraries (#7486) @jlowe
• Correctly compile benchmarks (#7485) @robertmaynard
• Fix bool column corruption with ORC Reader (#7483) @rgsl888prabhu
• Fix __repr__ for categorical dtype (#7476) @galipremsagar
• Java cleaner synchronization (#7474) @abellina
• Fix java float/double parsing tests (#7473) @revans2
• Pass stream and user resource to make_default_constructed_scalar (#7469) @magnatelee
• Improve stability of dask_cudf.DataFrame.var and dask_cudf.DataFrame.std (#7453) @rjzamora
• Missing device_storage_dispatch change affecting cudf::gather (#7449) @codereport
• fix cuFile JNI compile errors (#7445) @rongou
• Support Series.__setitem__ with key to a new row (#7443) @isVoid
• Fix BUG: Exception when PYTHONOPTIMIZE=2 (#7434) @skirui-source
• Make inclusive scan safe for cases with leading nulls (#7432) @magnatelee
• Fix typo in list_device_view::pair_rep_end() (#7423) @mythrocks
• Fix string to double conversion and row equivalent comparison (#7410) @ttnghia
• Fix thrust failure when transfering data from device_vector to host_vector with vectors of size 1 (#7382) @ttnghia
• Fix std::exeception catch-by-reference gcc9 compile error (#7380) @davidwendt
• Fix skiprows issue with ORC Reader (#7359) @rgsl888prabhu
• fix Arrow CMake file (#7358) @rongou
• Fix lists::contains() for NaN and Decimals (#7349) @mythrocks
• Handle cupy array in Dataframe.__setitem__ (#7340) @galipremsagar
• Fix invalid-device-fn error in cudf::strings::replace_re with multiple regex's (#7336) @davidwendt
• FIX Add codecov upload block to gpu script (#6860) @dillon-cullinan

📖 Documentation

• Fix join API doxygen (#7890) @shwina
• Add Resources to README. (#7697) @bdice
• Add isin examples in Docstring (#7479) @galipremsagar
• Resolving unlinked type shorthands in cudf doc (#7416) @isVoid
• Fix typo in regex.md doc page (#7363) @davidwendt
• Fix incorrect strings_column_view::chars_size documentation (#7360) @jlowe

🚀 New Features

• Enable basic reductions for decimal columns (#7776) @ChrisJar
• Enable join on decimal columns (#7764) @ChrisJar
• Allow merging index column with data column using keyword "on" (#7736) @skirui-source
• Implement DecimalColumn + Scalar and add cudf.Scalars of Decimal64Dtype (#7732) @brandon-b-miller
• Add support for unique groupby aggregation (#7726) @shwina
• Expose libcudf's label_bins function to cudf (#7724) @vyasr
• Adding support for equi-join on struct (#7720) @hyperbolic2346
• Add decimal column comparison operations (#7716) @isVoid
• Implement scan operations for decimal columns (#7707) @ChrisJar
• Enable typecasting between decimal and int (#7691) @ChrisJar
• Enable decimal support in parquet writer (#7673) @devavret
• Adds list.unique API (#7664) @isVoid
• Fix NaN handling in drop_list_duplicates (#7662) @ttnghia
• Add lists.sort_values API (#7657) @isVoid
• Add is_integer API that can check for the validity of a string-to-integer conversion (#7642) @ttnghia
• Adds explode API (#7607) @isVoid
• Adds list.take, python binding for cudf::lists::segmented_gather (#7591) @isVoid
• Implement cudf::label_bins() (#7554) @vyasr
• Add Python bindings for lists::contains (#7547) @skirui-source
• cudf::row_bit_count() support. (#7534) @nvdbaranec
• Implement drop_list_duplicates (#7528) @ttnghia
• Add Python bindings for lists::extract_lists_element (#7505) @skirui-source
• Add explode_outer and explode_outer_position (#7499) @hyperbolic2346
• Match Pandas logic for comparing two objects with nulls (#7490) @brandon-b-miller
• Add struct support to parquet writer (#7461) @devavret
• Enable type conversion from float to decimal type (#7450) @ChrisJar
• Add cython for converting strings/fixed-point functions (#7429) @davidwendt
• Add struct column support to cudf::sort and cudf::sorted_order (#7422) @karthikeyann
• Implement groupby collect_set (#7420) @ttnghia
• Merge branch-0.18 into branch-0.19 (#7411) @raydouglass
• Refactor strings column factories (#7397) @harrism
• Add groupby scan operations (sort groupby) (#7387) @karthikeyann
• Add cudf::explode_position (#7376) @hyperbolic2346
• Add string conversion to/from decimal values libcudf APIs (#7364) @davidwendt
• Add groupby SUM_OF_SQUARES support (#7362) @karthikeyann
• Add Series.drop api (#7304) @isVoid
• get_json_object() implementation (#7286) @nvdbaranec
• Python API for LIstMethods.len() (#7283) @isVoid
• Support null_policy::EXCLUDE for COLLECT rolling aggregation (#7264) @mythrocks
• Add support for special tokens in nvtext::subword_tokenizer (#7254) @davidwendt
• Fix inplace update of data and add Series.update (#7201) @galipremsagar
• Implement cudf::group_by (hash) for decimal32 and decimal64 (#7190) @codereport
• Adding support to specify "level" parameter for Dataframe.rename (#7135) @skirui-source

🛠️ Improvements

• fix GDS include path for version 0.95 (#7877) @rongou
• Update dask + distributed to 2021.4.0 (#7858) @jakirkham
• Add ability to extract include dirs from CUDF_HOME (#7848) @galipremsagar
• Add USE_GDS as an option in build script (#7833) @pxLi
• add an allocate method with stream in java DeviceMemoryBuffer (#7826) @rongou
• Constrain dask and distributed versions to 2021.3.1 (#7825) @shwina
• Revert dask versioning of concat dispatch (#7823) @galipremsagar
• add copy methods in Java memory buffer (#7791) @rongou
• Update README and CONTRIBUTING for 0.19 (#7778) @robertmaynard
• Allow hash_partition to take a seed value (#7771) @magnatelee
• Turn on NVTX by default in java build (#7761) @tgravescs
• Add Java bindings to join gather map APIs (#7751) @jlowe
• Add replacements column support for Java replaceNulls (#7750) @jlowe
• Add Java bindings for row_bit_count (#7749) @jlowe
• Remove unused JVM array creation (#7748) @jlowe
• Added JNI support for new is_integer (#7739) @revans2
• Create and promote library aliases in libcudf installations (#7734) @trxcllnt
• Support groupby operations for decimal dtypes (#7731) @vyasr
• Memory map the input file only when GDS compatiblity mode is not used (#7717) @vuule
• Replace device_vector with device_uvector in null_mask (#7715) @harrism
• Struct hashing support for SerialMurmur3 and SparkMurmur3 (#7714) @jlowe
• Add gbenchmark for nvtext replace-tokens function (#7708) @davidwendt
• Use stream in groupby calls (#7705) @karthikeyann
• Update codeowners file (#7701) @ajschmidt8
• Cleanup groupby to use host_span, device_span, device_uvector (#7698) @karthikeyann
• Add gbenchmark for nvtext ngrams functions (#7693) @davidwendt
• Misc Python/Cython optimizations (#7686) @shwina
• Add gbenchmark for nvtext tokenize functions (#7684) @davidwendt
• Add column_device_view to orc writer (#7676) @kaatish
• cudf_kafka now uses cuDF CMake export targets (CPM) (#7674) @robertmaynard
• Add gbenchmark for nvtext normalize functions (#7668) @davidwendt
• Resolve unnecessary import of thrust/optional.hpp in types.hpp (#7667) @vyasr
• Feature/optimize accessor copy (#7660) @vyasr
• Fix find_package(cudf) (#7658) @trxcllnt
• Work-around for gcc7 compile error on Centos7 (#7652) @davidwendt
• Add in JNI support for count_elements (#7651) @revans2
• Fix issues with building cudf in a non-conda environment (#7647) @galipremsagar
• Refactor ConfigureCUDA to not conditionally insert compiler flags (#7643) @robertmaynard
• Add gbenchmark for converting strings to/from timestamps (#7641) @davidwendt
• Handle constructing a cudf.Scalar from a cudf.Scalar (#7639) @shwina
• Add in JNI support for table partition (#7637) @revans2
• Add explicit fixed_point merge test (#7635) @codereport
• Add JNI support for IDENTITY hash partitioning (#7626) @revans2
• Java support on explode_outer (#7625) @sperlingxx
• Java support of casting string from/to decimal (#7623) @sperlingxx
• Convert cudf::concatenate APIs to use spans and device_uvector (#7621) @harrism
• Add gbenchmark for cudf::strings::translate function (#7617) @davidwendt
• Use file(COPY ) over file(INSTALL ) so cmake output is reduced (#7616) @robertmaynard
• Use rmm::device_uvector in place of rmm::device_vector for ORC reader/writer and cudf::io::column_buffer (#7614) @vuule
• Refactor Java host-side buffer concatenation to expose separate steps (#7610) @jlowe
• Add gbenchmarks for string substrings functions (#7603) @davidwendt
• Refactor string conversion check (#7599) @ttnghia
• JNI: Pass names of children struct columns to native Arrow IPC writer (#7598) @firestarman
• Revert "ENH Fix stale GHA and prevent duplicates " (#7595) @mike-wendt
• ENH Fix stale GHA and prevent duplicates (#7594) @mike-wendt
• Fix auto-detecting GPU architectures (#7593) @trxcllnt
• Reduce cudf library size (#7583) @robertmaynard
• Optimize cudf::make_strings_column for long strings (#7576) @davidwendt
• Always build and export the cudf::cudftestutil target (#7574) @trxcllnt
• Eliminate literal parameters to uvector::set_element_async and device_scalar::set_value (#7563) @harrism
• Add gbenchmark for strings::concatenate (#7560) @davidwendt
• Update Changelog Link (#7550) @ajschmidt8
• Add gbenchmarks for strings replace regex functions (#7541) @davidwendt
• Add __repr__ for Column and ColumnAccessor (#7531) @shwina
• Support Decimal DIV changes in cudf (#7527) @razajafri
• Remove unneeded step parameter from strings::detail::copy_slice (#7525) @davidwendt
• Use device_uvector, device_span in sort groupby (#7523) @karthikeyann
• Add gbenchmarks for strings extract function (#7522) @davidwendt
• Rename ARROW_STATIC_LIB because it conflicts with one in FindArrow.cmake (#7518) @trxcllnt
• Reduce compile time/size for scan.cu (#7516) @davidwendt
• Change device_vector to device_uvector in nvtext source files (#7512) @davidwendt
• Removed unneeded includes from traits.hpp (#7509) @davidwendt
• FIX Remove random build directory generation for ccache (#7508) @dillon-cullinan
• xfail failing pytest in pandas 1.2.3 (#7507) @galipremsagar
• JNI bit cast (#7493) @revans2
• Combine rolling window function tests (#7480) @mythrocks
• Prepare Changelog for Automation (#7477) @ajschmidt8
• Java support for explode position (#7471) @sperlingxx
• Update 0.18 changelog entry (#7463) @ajschmidt8
• JNI: Support skipping nulls for collect aggregation (#7457) @firestarman
• Join APIs that return gathermaps (#7454) @shwina
• Remove dependence on managed memory for multimap test (#7451) @jrhemstad
• Use cuFile for Parquet IO when available (#7444) @vuule
• Statistics cleanup (#7439) @kaatish
• Add gbenchmarks for strings filter functions (#7438) @davidwendt
• fixed_point + cudf::binary_operation API Changes (#7435) @codereport
• Improve string gather performance (#7433) @jlowe
• Don't use user resource for a temporary allocation in sort_by_key (#7431) @magnatelee
• Detail APIs for datetime functions (#7430) @magnatelee
• Replace thrust::max_element with thrust::reduce in strings findall_re (#7428) @davidwendt
• Add gbenchmark for strings split/split_record functions (#7427) @davidwendt
• Update JNI build to use CMAKE_CUDA_ARCHITECTURES (#7425) @jlowe
• Change nvtext::load_vocabulary_file to return a unique ptr (#7424) @davidwendt
• Simplify type dispatch with device_storage_dispatch (#7419) @codereport
• Java support for casting of nested child columns (#7417) @razajafri
• Improve scalar string replace performance for long strings (#7415) @jlowe
• Remove unneeded temporary device vector for strings scatter specialization (#7409) @davidwendt
• bitmask_or implementation with bitmask refactor (#7406) @rwlee
• Add other cudf::strings::replace functions to current strings replace gbenchmark (#7403) @davidwendt
• Clean up included headers in device_operators.cuh (#7401) @codereport
• Move nullable index iterator to indexalator factory (#7399) @davidwendt
• ENH Pass ccache variables to conda recipe & use Ninja in CI (#7398) @Ethyling
• upgrade maven-antrun-plugin to support maven parallel builds (#7393) @rongou
• Add gbenchmark for strings find/contains functions (#7392) @davidwendt
• Use CMAKE_CUDA_ARCHITECTURES (#7391) @robertmaynard
• Refactor libcudf strings::replace to use make_strings_children utility (#7384) @davidwendt
• Added in JNI support for out of core sort algorithm (#7381) @revans2
• Upgrade pandas to 1.2 (#7375) @galipremsagar
• Rename logical_cast to bit_cast and allow additional conversions (#7373) @ttnghia
• jitify 2 support (#7372) @cwharris
• compile_udf: Cache PTX for similar functions (#7371) @gmarkall
• Add string scalar replace benchmark (#7369) @jlowe
• Add gbenchmark for strings contains_re/count_re functions (#7366) @davidwendt
• Update orc reader and writer fuzz tests (#7357) @galipremsagar
• Improve url_decode performance for long strings (#7353) @jlowe
• cudf::ast Small Refactorings (#7352) @codereport
• Remove std::cout and print in the scatter test function EmptyListsOfNullableStrings. (#7342) @ttnghia
• Use cudf::detail::make_counting_transform_iterator (#7338) @codereport
• Change block size parameter from a global to a template param. (#7333) @nvdbaranec
• Partial clean up of ORC writer (#7324) @vuule
• Add gbenchmark for cudf::strings::to_lower (#7316) @davidwendt
• Update Java bindings version to 0.19-SNAPSHOT (#7307) @pxLi
• Move cudf::test::make_counting_transform_iterator to cudf/detail/iterator.cuh (#7306) @codereport
• Use string literals in fixed_point release_asserts (#7303) @codereport
• Fix merge conflicts for #7295 (#7297) @ajschmidt8
• Add UTF-8 chars to create_random_column<string_view> benchmark utility (#7292) @davidwendt
• Abstracting block reduce and block scan from cuIO kernels with cub apis (#7278) @rgsl888prabhu
• Build.sh use cmake --build to drive build system invocation (#7270) @robertmaynard
• Refactor dictionary support for reductions any/all (#7242) @davidwendt
• Replace stream.value() with stream for stream_view args (#7236) @karthikeyann
• Interval index and interval_range (#7182) @marlenezw
• avro reader integration tests (#7156) @cwharris
• Rework libcudf CMakeLists.txt to export targets for CPM (#7107) @trxcllnt
• Adding Interval Dtype (#6984) @marlenezw
• Cleaning up for loops with make_(counting_)transform_iterator (#6546) @codereport

🚨 Breaking Changes

• Allow hash_partition to take a seed value (#7771) @magnatelee
• Allow merging index column with data column using keyword "on" (#7736) @skirui-source
• Change JNI API to avoid loading native dependencies when creating sort order classes. (#7729) @revans2
• Replace device_vector with device_uvector in null_mask (#7715) @harrism
• Don't identify decimals as strings. (#7710) @vyasr
• Fix Java Parquet write after writer API changes (#7655) @revans2
• Convert cudf::concatenate APIs to use spans and device_uvector (#7621) @harrism
• Update missing docstring examples in python public APIs (#7546) @galipremsagar
• Remove unneeded step parameter from strings::detail::copy_slice (#7525) @davidwendt
• Rename ARROW_STATIC_LIB because it conflicts with one in FindArrow.cmake (#7518) @trxcllnt
• Match Pandas logic for comparing two objects with nulls (#7490) @brandon-b-miller
• Add struct support to parquet writer (#7461) @devavret
• Join APIs that return gathermaps (#7454) @shwina
• fixed_point + cudf::binary_operation API Changes (#7435) @codereport
• Fix BUG: Exception when PYTHONOPTIMIZE=2 (#7434) @skirui-source
• Change nvtext::load_vocabulary_file to return a unique ptr (#7424) @davidwendt
• Refactor strings column factories (#7397) @harrism
• Use CMAKE_CUDA_ARCHITECTURES (#7391) @robertmaynard
• Upgrade pandas to 1.2 (#7375) @galipremsagar
• Rename logical_cast to bit_cast and allow additional conversions (#7373) @ttnghia
• Rework libcudf CMakeLists.txt to export targets for CPM (#7107) @trxcllnt

🐛 Bug Fixes

• Fix a NameError in meta dispatch API (#7996) @galipremsagar
• Reindex in DataFrame.__setitem__ (#7957) @galipremsagar
• jitify direct-to-cubin compilation and caching. (#7919) @cwharris
• Use dynamic cudart for nvcomp in java build (#7896) @abellina
• fix "incompatible redefinition" warnings (#7894) @cwharris
• cudf consistently specifies the cuda runtime (#7887) @robertmaynard
• disable verbose output for jitify_preprocess (#7886) @cwharris
• CMake jit_preprocess_files function only runs when needed (#7872) @robertmaynard
• Push DeviceScalar construction into cython for list.contains (#7864) @brandon-b-miller
• cudf now sets an install rpath of $ORIGIN (#7863) @robertmaynard
• Don't install Thrust examples, tests, docs, and python files (#7811) @robertmaynard
• Sort by index in groupby tests more consistently (#7802) @shwina
• Revert "Update conda recipes pinning of repo dependencies (#7743)" (#7793) @raydouglass
• Add decimal column handling in copy_type_metadata (#7788) @shwina
• Add column names validation in parquet writer (#7786) @galipremsagar
• Fix Java explode outer unit tests (#7782) @jlowe
• Fix compiler warning about non-POD types passed through ellipsis (#7781) @jrhemstad
• User resource fix for replace_nulls (#7769) @magnatelee
• Fix type dispatch for columnar replace_nulls (#7768) @jlowe
• Add ignore_order parameter to dask-cudf concat dispatch (#7765) @galipremsagar
• Fix slicing and arrow representations of decimal columns (#7755) @vyasr
• Fixing issue with explode_outer position not nulling position entries of null rows (#7754) @hyperbolic2346
• Implement scatter for struct columns (#7752) @ttnghia
• Fix data corruption in string columns (#7746) @galipremsagar
• Fix string length in stripe dictionary building (#7744) @kaatish
• Update conda recipes pinning of repo dependencies (#7743) @mike-wendt
• Enable dask dispatch to cuDF's is_categorical_dtype for cuDF objects (#7740) @brandon-b-miller
• Fix dictionary size computation in ORC writer (#7737) @vuule
• Fix cudf::cast overflow for decimal64 to int32_t or smaller in certain cases (#7733) @codereport
• Change JNI API to avoid loading native dependencies when creating sort order classes. (#7729) @revans2
• Disable column_view data accessors for unsupported types (#7725) @jrhemstad
• Materialize RangeIndex when index=True in parquet writer (#7711) @galipremsagar
• Don't identify decimals as strings. (#7710) @vyasr
• Fix return type of DataFrame.argsort (#7706) @galipremsagar
• Fix/correct cudf installed package requirements (#7688) @robertmaynard
• Fix SparkMurmurHash3_32 hash inconsistencies with Apache Spark (#7672) @jlowe
• Fix ORC reader issue with reading empty string columns (#7656) @rgsl888prabhu
• Fix Java Parquet write after writer API changes (#7655) @revans2
• Fixing empty null lists throwing explode_outer for a loop. (#7649) @hyperbolic2346
• Fix internal compiler error during JNI Docker build (#7645) @jlowe
• Fix Debug build break with device_uvectors in grouped_rolling.cu (#7633) @mythrocks
• Parquet reader: Fix issue when using skip_rows on non-nested columns containing nulls (#7627) @nvdbaranec
• Fix ORC reader for empty DataFrame/Table (#7624) @rgsl888prabhu
• Fix specifying GPU architecture in JNI build (#7612) @jlowe
• Fix ORC writer OOM issue (#7605) @vuule
• Fix 0.18 --> 0.19 automerge (#7589) @kkraus14
• Fix ORC issue with incorrect timestamp nanosecond values (#7581) @vuule
• Fix missing Dask imports (#7580) @kkraus14
• CMAKE_CUDA_ARCHITECTURES doesn't change when build-system invokes cmake (#7579) @robertmaynard
• Another fix for offsets_end() iterator in lists_column_view (#7575) @ttnghia
• Fix ORC writer output corruption with string columns (#7565) @vuule
• Fix cudf::lists::sort_lists failing for sliced column (#7564) @ttnghia
• FIX Fix Anaconda upload args (#7558) @dillon-cullinan
• Fix index mismatch issue in equality related APIs (#7555) @galipremsagar
• FIX Revert gpuci_conda_retry on conda file output locations (#7552) @dillon-cullinan
• Fix offset_end iterator for lists_column_view, which was not correctl… (#7551) @ttnghia
• Fix no such file dlpack.h error when build libcudf (#7549) @chenrui17
• Update missing docstring examples in python public APIs (#7546) @galipremsagar
• Decimal32 Build Fix (#7544) @razajafri
• FIX Retry conda output location (#7540) @dillon-cullinan
• fix missing renames of dask git branches from master to main (#7535) @kkraus14
• Remove detail from device_span (#7533) @rwlee
• Change dask and distributed branch to main (#7532) @dantegd
• Update JNI build to use CUDF_USE_ARROW_STATIC (#7526) @jlowe
• Make sure rmm::rmm CMake target is visibile to cudf users (#7524) @robertmaynard
• Fix contiguous_split not properly handling output partitions > 2 GB. (#7515) @nvdbaranec
• Change jit launch to safe_launch (#7510) @devavret
• Fix comparison between Datetime/Timedelta columns and NULL scalars (#7504) @brandon-b-miller
• Fix off-by-one error in char-parallel string scalar replace (#7502) @jlowe
• Fix JNI deprecation of all, put it on the wrong version before (#7501) @revans2
• Fix Series/Dataframe Mixed Arithmetic (#7491) @brandon-b-miller
• Fix JNI build after removal of libcudf sub-libraries (#7486) @jlowe
• Correctly compile benchmarks (#7485) @robertmaynard
• Fix bool column corruption with ORC Reader (#7483) @rgsl888prabhu
• Fix __repr__ for categorical dtype (#7476) @galipremsagar
• Java cleaner synchronization (#7474) @abellina
• Fix java float/double parsing tests (#7473) @revans2
• Pass stream and user resource to make_default_constructed_scalar (#7469) @magnatelee
• Improve stability of dask_cudf.DataFrame.var and dask_cudf.DataFrame.std (#7453) @rjzamora
• Missing device_storage_dispatch change affecting cudf::gather (#7449) @codereport
• fix cuFile JNI compile errors (#7445) @rongou
• Support Series.__setitem__ with key to a new row (#7443) @isVoid
• Fix BUG: Exception when PYTHONOPTIMIZE=2 (#7434) @skirui-source
• Make inclusive scan safe for cases with leading nulls (#7432) @magnatelee
• Fix typo in list_device_view::pair_rep_end() (#7423) @mythrocks
• Fix string to double conversion and row equivalent comparison (#7410) @ttnghia
• Fix thrust failure when transfering data from device_vector to host_vector with vectors of size 1 (#7382) @ttnghia
• Fix std::exeception catch-by-reference gcc9 compile error (#7380) @davidwendt
• Fix skiprows issue with ORC Reader (#7359) @rgsl888prabhu
• fix Arrow CMake file (#7358) @rongou
• Fix lists::contains() for NaN and Decimals (#7349) @mythrocks
• Handle cupy array in Dataframe.__setitem__ (#7340) @galipremsagar
• Fix invalid-device-fn error in cudf::strings::replace_re with multiple regex's (#7336) @davidwendt
• FIX Add codecov upload block to gpu script (#6860) @dillon-cullinan

📖 Documentation

• Fix join API doxygen (#7890) @shwina
• Add Resources to README. (#7697) @bdice
• Add isin examples in Docstring (#7479) @galipremsagar
• Resolving unlinked type shorthands in cudf doc (#7416) @isVoid
• Fix typo in regex.md doc page (#7363) @davidwendt
• Fix incorrect strings_column_view::chars_size documentation (#7360) @jlowe

🚀 New Features

• Enable basic reductions for decimal columns (#7776) @ChrisJar
• Enable join on decimal columns (#7764) @ChrisJar
• Allow merging index column with data column using keyword "on" (#7736) @skirui-source
• Implement DecimalColumn + Scalar and add cudf.Scalars of Decimal64Dtype (#7732) @brandon-b-miller
• Add support for unique groupby aggregation (#7726) @shwina
• Expose libcudf's label_bins function to cudf (#7724) @vyasr
• Adding support for equi-join on struct (#7720) @hyperbolic2346
• Add decimal column comparison operations (#7716) @isVoid
• Implement scan operations for decimal columns (#7707) @ChrisJar
• Enable typecasting between decimal and int (#7691) @ChrisJar
• Enable decimal support in parquet writer (#7673) @devavret
• Adds list.unique API (#7664) @isVoid
• Fix NaN handling in drop_list_duplicates (#7662) @ttnghia
• Add lists.sort_values API (#7657) @isVoid
• Add is_integer API that can check for the validity of a string-to-integer conversion (#7642) @ttnghia
• Adds explode API (#7607) @isVoid
• Adds list.take, python binding for cudf::lists::segmented_gather (#7591) @isVoid
• Implement cudf::label_bins() (#7554) @vyasr
• Add Python bindings for lists::contains (#7547) @skirui-source
• cudf::row_bit_count() support. (#7534) @nvdbaranec
• Implement drop_list_duplicates (#7528) @ttnghia
• Add Python bindings for lists::extract_lists_element (#7505) @skirui-source
• Add explode_outer and explode_outer_position (#7499) @hyperbolic2346
• Match Pandas logic for comparing two objects with nulls (#7490) @brandon-b-miller
• Add struct support to parquet writer (#7461) @devavret
• Enable type conversion from float to decimal type (#7450) @ChrisJar
• Add cython for converting strings/fixed-point functions (#7429) @davidwendt
• Add struct column support to cudf::sort and cudf::sorted_order (#7422) @karthikeyann
• Implement groupby collect_set (#7420) @ttnghia
• Merge branch-0.18 into branch-0.19 (#7411) @raydouglass
• Refactor strings column factories (#7397) @harrism
• Add groupby scan operations (sort groupby) (#7387) @karthikeyann
• Add cudf::explode_position (#7376) @hyperbolic2346
• Add string conversion to/from decimal values libcudf APIs (#7364) @davidwendt
• Add groupby SUM_OF_SQUARES support (#7362) @karthikeyann
• Add Series.drop api (#7304) @isVoid
• get_json_object() implementation (#7286) @nvdbaranec
• Python API for LIstMethods.len() (#7283) @isVoid
• Support null_policy::EXCLUDE for COLLECT rolling aggregation (#7264) @mythrocks
• Add support for special tokens in nvtext::subword_tokenizer (#7254) @davidwendt
• Fix inplace update of data and add Series.update (#7201) @galipremsagar
• Implement cudf::group_by (hash) for decimal32 and decimal64 (#7190) @codereport
• Adding support to specify "level" parameter for Dataframe.rename (#7135) @skirui-source

🛠️ Improvements

• fix GDS include path for version 0.95 (#7877) @rongou
• Update dask + distributed to 2021.4.0 (#7858) @jakirkham
• Add ability to extract include dirs from CUDF_HOME (#7848) @galipremsagar
• Add USE_GDS as an option in build script (#7833) @pxLi
• add an allocate method with stream in java DeviceMemoryBuffer (#7826) @rongou
• Constrain dask and distributed versions to 2021.3.1 (#7825) @shwina
• Revert dask versioning of concat dispatch (#7823) @galipremsagar
• add copy methods in Java memory buffer (#7791) @rongou
• Update README and CONTRIBUTING for 0.19 (#7778) @robertmaynard
• Allow hash_partition to take a seed value (#7771) @magnatelee
• Turn on NVTX by default in java build (#7761) @tgravescs
• Add Java bindings to join gather map APIs (#7751) @jlowe
• Add replacements column support for Java replaceNulls (#7750) @jlowe
• Add Java bindings for row_bit_count (#7749) @jlowe
• Remove unused JVM array creation (#7748) @jlowe
• Added JNI support for new is_integer (#7739) @revans2
• Create and promote library aliases in libcudf installations (#7734) @trxcllnt
• Support groupby operations for decimal dtypes (#7731) @vyasr
• Memory map the input file only when GDS compatiblity mode is not used (#7717) @vuule
• Replace device_vector with device_uvector in null_mask (#7715) @harrism
• Struct hashing support for SerialMurmur3 and SparkMurmur3 (#7714) @jlowe
• Add gbenchmark for nvtext replace-tokens function (#7708) @davidwendt
• Use stream in groupby calls (#7705) @karthikeyann
• Update codeowners file (#7701) @ajschmidt8
• Cleanup groupby to use host_span, device_span, device_uvector (#7698) @karthikeyann
• Add gbenchmark for nvtext ngrams functions (#7693) @davidwendt
• Misc Python/Cython optimizations (#7686) @shwina
• Add gbenchmark for nvtext tokenize functions (#7684) @davidwendt
• Add column_device_view to orc writer (#7676) @kaatish
• cudf_kafka now uses cuDF CMake export targets (CPM) (#7674) @robertmaynard
• Add gbenchmark for nvtext normalize functions (#7668) @davidwendt
• Resolve unnecessary import of thrust/optional.hpp in types.hpp (#7667) @vyasr
• Feature/optimize accessor copy (#7660) @vyasr
• Fix find_package(cudf) (#7658) @trxcllnt
• Work-around for gcc7 compile error on Centos7 (#7652) @davidwendt
• Add in JNI support for count_elements (#7651) @revans2
• Fix issues with building cudf in a non-conda environment (#7647) @galipremsagar
• Refactor ConfigureCUDA to not conditionally insert compiler flags (#7643) @robertmaynard
• Add gbenchmark for converting strings to/from timestamps (#7641) @davidwendt
• Handle constructing a cudf.Scalar from a cudf.Scalar (#7639) @shwina
• Add in JNI support for table partition (#7637) @revans2
• Add explicit fixed_point merge test (#7635) @codereport
• Add JNI support for IDENTITY hash partitioning (#7626) @revans2
• Java support on explode_outer (#7625) @sperlingxx
• Java support of casting string from/to decimal (#7623) @sperlingxx
• Convert cudf::concatenate APIs to use spans and device_uvector (#7621) @harrism
• Add gbenchmark for cudf::strings::translate function (#7617) @davidwendt
• Use file(COPY ) over file(INSTALL ) so cmake output is reduced (#7616) @robertmaynard
• Use rmm::device_uvector in place of rmm::device_vector for ORC reader/writer and cudf::io::column_buffer (#7614) @vuule
• Refactor Java host-side buffer concatenation to expose separate steps (#7610) @jlowe
• Add gbenchmarks for string substrings functions (#7603) @davidwendt
• Refactor string conversion check (#7599) @ttnghia
• JNI: Pass names of children struct columns to native Arrow IPC writer (#7598) @firestarman
• Revert "ENH Fix stale GHA and prevent duplicates " (#7595) @mike-wendt
• ENH Fix stale GHA and prevent duplicates (#7594) @mike-wendt
• Fix auto-detecting GPU architectures (#7593) @trxcllnt
• Reduce cudf library size (#7583) @robertmaynard
• Optimize cudf::make_strings_column for long strings (#7576) @davidwendt
• Always build and export the cudf::cudftestutil target (#7574) @trxcllnt
• Eliminate literal parameters to uvector::set_element_async and device_scalar::set_value (#7563) @harrism
• Add gbenchmark for strings::concatenate (#7560) @davidwendt
• Update Changelog Link (#7550) @ajschmidt8
• Add gbenchmarks for strings replace regex functions (#7541) @davidwendt
• Add __repr__ for Column and ColumnAccessor (#7531) @shwina
• Support Decimal DIV changes in cudf (#7527) @razajafri
• Remove unneeded step parameter from strings::detail::copy_slice (#7525) @davidwendt
• Use device_uvector, device_span in sort groupby (#7523) @karthikeyann
• Add gbenchmarks for strings extract function (#7522) @davidwendt
• Rename ARROW_STATIC_LIB because it conflicts with one in FindArrow.cmake (#7518) @trxcllnt
• Reduce compile time/size for scan.cu (#7516) @davidwendt
• Change device_vector to device_uvector in nvtext source files (#7512) @davidwendt
• Removed unneeded includes from traits.hpp (#7509) @davidwendt
• FIX Remove random build directory generation for ccache (#7508) @dillon-cullinan
• xfail failing pytest in pandas 1.2.3 (#7507) @galipremsagar
• JNI bit cast (#7493) @revans2
• Combine rolling window function tests (#7480) @mythrocks
• Prepare Changelog for Automation (#7477) @ajschmidt8
• Java support for explode position (#7471) @sperlingxx
• Update 0.18 changelog entry (#7463) @ajschmidt8
• JNI: Support skipping nulls for collect aggregation (#7457) @firestarman
• Join APIs that return gathermaps (#7454) @shwina
• Remove dependence on managed memory for multimap test (#7451) @jrhemstad
• Use cuFile for Parquet IO when available (#7444) @vuule
• Statistics cleanup (#7439) @kaatish
• Add gbenchmarks for strings filter functions (#7438) @davidwendt
• fixed_point + cudf::binary_operation API Changes (#7435) @codereport
• Improve string gather performance (#7433) @jlowe
• Don't use user resource for a temporary allocation in sort_by_key (#7431) @magnatelee
• Detail APIs for datetime functions (#7430) @magnatelee
• Replace thrust::max_element with thrust::reduce in strings findall_re (#7428) @davidwendt
• Add gbenchmark for strings split/split_record functions (#7427) @davidwendt
• Update JNI build to use CMAKE_CUDA_ARCHITECTURES (#7425) @jlowe
• Change nvtext::load_vocabulary_file to return a unique ptr (#7424) @davidwendt
• Simplify type dispatch with device_storage_dispatch (#7419) @codereport
• Java support for casting of nested child columns (#7417) @razajafri
• Improve scalar string replace performance for long strings (#7415) @jlowe
• Remove unneeded temporary device vector for strings scatter specialization (#7409) @davidwendt
• bitmask_or implementation with bitmask refactor (#7406) @rwlee
• Add other cudf::strings::replace functions to current strings replace gbenchmark (#7403) @davidwendt
• Clean up included headers in device_operators.cuh (#7401) @codereport
• Move nullable index iterator to indexalator factory (#7399) @davidwendt
• ENH Pass ccache variables to conda recipe & use Ninja in CI (#7398) @Ethyling
• upgrade maven-antrun-plugin to support maven parallel builds (#7393) @rongou
• Add gbenchmark for strings find/contains functions (#7392) @davidwendt
• Use CMAKE_CUDA_ARCHITECTURES (#7391) @robertmaynard
• Refactor libcudf strings::replace to use make_strings_children utility (#7384) @davidwendt
• Added in JNI support for out of core sort algorithm (#7381) @revans2
• Upgrade pandas to 1.2 (#7375) @galipremsagar
• Rename logical_cast to bit_cast and allow additional conversions (#7373) @ttnghia
• jitify 2 support (#7372) @cwharris
• compile_udf: Cache PTX for similar functions (#7371) @gmarkall
• Add string scalar replace benchmark (#7369) @jlowe
• Add gbenchmark for strings contains_re/count_re functions (#7366) @davidwendt
• Update orc reader and writer fuzz tests (#7357) @galipremsagar
• Improve url_decode performance for long strings (#7353) @jlowe
• cudf::ast Small Refactorings (#7352) @codereport
• Remove std::cout and print in the scatter test function EmptyListsOfNullableStrings. (#7342) @ttnghia
• Use cudf::detail::make_counting_transform_iterator (#7338) @codereport
• Change block size parameter from a global to a template param. (#7333) @nvdbaranec
• Partial clean up of ORC writer (#7324) @vuule
• Add gbenchmark for cudf::strings::to_lower (#7316) @davidwendt
• Update Java bindings version to 0.19-SNAPSHOT (#7307) @pxLi
• Move cudf::test::make_counting_transform_iterator to cudf/detail/iterator.cuh (#7306) @codereport
• Use string literals in fixed_point release_asserts (#7303) @codereport
• Fix merge conflicts for #7295 (#7297) @ajschmidt8
• Add UTF-8 chars to create_random_column<string_view> benchmark utility (#7292) @davidwendt
• Abstracting block reduce and block scan from cuIO kernels with cub apis (#7278) @rgsl888prabhu
• Build.sh use cmake --build to drive build system invocation (#7270) @robertmaynard
• Refactor dictionary support for reductions any/all (#7242) @davidwendt
• Replace stream.value() with stream for stream_view args (#7236) @karthikeyann
• Interval index and interval_range (#7182) @marlenezw
• avro reader integration tests (#7156) @cwharris
• Rework libcudf CMakeLists.txt to export targets for CPM (#7107) @trxcllnt
• Adding Interval Dtype (#6984) @marlenezw
• Cleaning up for loops with make_(counting_)transform_iterator (#6546) @codereport

Breaking Changes 🚨

• Default groupby to sort=False (#7180) @isVoid
• Add libcudf API for parsing of ORC statistics (#7136) @vuule
• Replace ORC writer api with class (#7099) @rgsl888prabhu
• Pack/unpack functionality to convert tables to and from a serialized format. (#7096) @nvdbaranec
• Replace parquet writer api with class (#7058) @rgsl888prabhu
• Add days check to cudf::is_timestamp using cuda::std::chrono classes (#7028) @davidwendt
• Fix default parameter values of write_csv and write_parquet (#6967) @vuule
• Align Series.groupby API to match Pandas (#6964) @kkraus14
• Share factorize implementation with Index and cudf module (#6885) @brandon-b-miller

Bug Fixes 🐛

• Remove incorrect std::move call on return variable (#7319) @davidwendt
• Fix failing CI ORC test (#7313) @vuule
• Disallow constructing frames from a ColumnAccessor (#7298) @shwina
• fix java cuFile tests (#7296) @rongou
• Fix style issues related to NumPy (#7279) @shwina
• Fix bug when iloc slice terminates at before-the-zero position (#7277) @isVoid
• Fix copying dtype metadata after calling libcudf functions (#7271) @shwina
• Move lists utility function definition out of header (#7266) @mythrocks
• Throw if bool column would cause incorrect result when writing to ORC (#7261) @vuule
• Use uvector in replace_nulls; Fix sort_helper::grouped_value doc (#7256) @isVoid
• Remove floating point types from cudf::sort fast-path (#7250) @davidwendt
• Disallow picking output columns from nested columns. (#7248) @devavret
• Fix loc for Series with a MultiIndex (#7243) @shwina
• Fix Arrow column test leaks (#7241) @tgravescs
• Fix test column vector leak (#7238) @kuhushukla
• Fix some bugs in java scalar support for decimal (#7237) @revans2
• Improve assert_eq handling of scalar (#7220) @isVoid
• Fix missing null_count() comparison in test framework and related failures (#7219) @nvdbaranec
• Remove floating point types from radix sort fast-path (#7215) @davidwendt
• Fixing parquet benchmarks (#7214) @rgsl888prabhu
• Handle various parameter combinations in replace API (#7207) @galipremsagar
• Export mock aws credentials for s3 tests (#7176) @ayushdg
• Add MultiIndex.rename API (#7172) @isVoid
• Fix importing list & struct types in from_arrow (#7162) @galipremsagar
• Fixing parquet precision writing failing if scale is equal to precision (#7146) @hyperbolic2346
• Update s3 tests to use moto_server (#7144) @ayushdg
• Fix JIT cache multi-process test flakiness in slow drives (#7142) @devavret
• Fix compilation errors in libcudf (#7138) @galipremsagar
• Fix compilation failure caused by -Wall addition. (#7134) @codereport
• Add informative error message for sep in CSV writer (#7095) @galipremsagar
• Add JIT cache per compute capability (#7090) @devavret
• Implement __hash__ method for ListDtype (#7081) @galipremsagar
• Only upload packages that were built (#7077) @raydouglass
• Fix comparisons between Series and cudf.NA (#7072) @brandon-b-miller
• Handle nan values correctly in Series.one_hot_encoding (#7059) @galipremsagar
• Add unstack() support for non-multiindexed dataframes (#7054) @isVoid
• Fix read_orc for decimal type (#7034) @rgsl888prabhu
• Fix backward compatibility of loading a 0.16 pkl file (#7033) @galipremsagar
• Decimal casts in JNI became a NOOP (#7032) @revans2
• Restore usual instance/subclass checking to cudf.DateOffset (#7029) @shwina
• Add days check to cudf::is_timestamp using cuda::std::chrono classes (#7028) @davidwendt
• Fix to_csv delimiter handling of timestamp format (#7023) @davidwendt
• Pin librdkakfa to gcc 7 compatible version (#7021) @raydouglass
• Fix fillna & dropna to also consider np.nan as a missing value (#7019) @galipremsagar
• Fix round operator's HALF_EVEN computation for negative integers (#7014) @nartal1
• Skip Thrust sort patch if already applied (#7009) @harrism
• Fix cudf::hash_partition for decimal32 and decimal64 (#7006) @codereport
• Fix Thrust unroll patch command (#7002) @harrism
• Fix loc behaviour when key of incorrect type is used (#6993) @shwina
• Fix int to datetime conversion in csv_read (#6991) @kaatish
• fix excluding cufile tests by default (#6988) @rongou
• Fix java cufile tests when cufile is not installed (#6987) @revans2
• Make cudf::round for fixed_point when scale = -decimal_places a no-op (#6975) @codereport
• Fix type comparison for java (#6970) @revans2
• Fix default parameter values of write_csv and write_parquet (#6967) @vuule
• Align Series.groupby API to match Pandas (#6964) @kkraus14
• Fix timestamp parsing in ORC reader for timezones without transitions (#6959) @vuule
• Fix typo in numerical.py (#6957) @rgsl888prabhu
• fixed_point_value double-shifts in fixed_point construction (#6950) @codereport
• fix libcu++ include path for jni (#6948) @rongou
• Fix groupby agg/apply behaviour when no key columns are provided (#6945) @shwina
• Avoid inserting null elements into join hash table when nulls are treated as unequal (#6943) @hyperbolic2346
• Fix cudf::merge gtest for dictionary columns (#6942) @davidwendt
• Pass numeric scalars of the same dtype through numeric binops (#6938) @brandon-b-miller
• Fix N/A detection for empty fields in CSV reader (#6922) @vuule
• Fix rmm_mode=managed parameter for gtests (#6912) @davidwendt
• Fix nullmask offset handling in parquet and orc writer (#6889) @kaatish
• Correct the sampling range when sampling with replacement (#6884) @ChrisJar
• Handle nested string columns with no children in contiguous_split. (#6864) @nvdbaranec
• Fix columns & index handling in dataframe constructor (#6838) @galipremsagar

Documentation 📖

• Update readme (#7318) @shwina
• Fix typo in cudf.core.column.string.extract docs (#7253) @adelevie
• Update doxyfile project number (#7161) @davidwendt
• Update 10 minutes to cuDF and CuPy with new APIs (#7158) @ChrisJar
• Cross link RMM & libcudf Doxygen docs (#7149) @ajschmidt8
• Add documentation for support dtypes in all IO formats (#7139) @galipremsagar
• Add groupby docs (#7100) @shwina
• Update cudf python docstrings with new null representation (<NA>) (#7050) @galipremsagar
• Make Doxygen comments formatting consistent (#7041) @vuule
• Add docs for working with missing data (#7010) @galipremsagar
• Remove warning in from_dlpack and to_dlpack methods (#7001) @miguelusque
• libcudf Developer Guide (#6977) @harrism
• Add JNI wrapper for the cuFile API (GDS) (#6940) @rongou

New Features 🚀

• Support numeric_only field for rank() (#7213) @isVoid
• Add support for cudf::binary_operation TRUE_DIV for decimal32 and decimal64 (#7198) @codereport
• Implement COLLECT rolling window aggregation (#7189) @mythrocks
• Add support for array-like inputs in cudf.get_dummies (#7181) @galipremsagar
• Default groupby to sort=False (#7180) @isVoid
• Add libcudf lists column count_elements API (#7173) @davidwendt
• Implement cudf::group_by (sort) for decimal32 and decimal64 (#7169) @codereport
• Add encoding and compression argument to CSV writer (#7168) @VibhuJawa
• cudf::rolling_window SUM support for decimal32 and decimal64 (#7147) @codereport
• Adding support for explode to cuDF (#7140) @hyperbolic2346
• Add libcudf API for parsing of ORC statistics (#7136) @vuule
• update GDS/cuFile location for 0.9 release (#7131) @rongou
• Add Segmented sort (#7122) @karthikeyann
• Add cudf::binary_operation NULL_MIN, NULL_MAX & NULL_EQUALS for decimal32 and decimal64 (#7119) @codereport
• Add scale and value methods to fixed_point (#7109) @codereport
• Replace ORC writer api with class (#7099) @rgsl888prabhu
• Pack/unpack functionality to convert tables to and from a serialized format. (#7096) @nvdbaranec
• Improve digitize API (#7071) @isVoid
• Add List types support in data generator (#7064) @galipremsagar
• cudf::scan support for decimal32 and decimal64 (#7063) @codereport
• cudf::rolling ROW_NUMBER support for decimal32 and decimal64 (#7061) @codereport
• Replace parquet writer api with class (#7058) @rgsl888prabhu
• Support contains() on lists of primitives (#7039) @mythrocks
• Implement cudf::rolling for decimal32 and decimal64 (#7037) @codereport
• Add ffill and bfill to string columns (#7036) @isVoid
• Enable round in cudf for DataFrame and Series (#7022) @ChrisJar
• Extend replace_nulls_policy to string and dictionary type (#7004) @isVoid
• Add segmented_gather(list_column, gather_list) (#7003) @karthikeyann
• Add method field to fillna for fixed width columns (#6998) @isVoid
• Manual merge of branch 0.17 into branch 0.18 (#6995) @shwina
• Implement cudf::reduce for decimal32 and decimal64 (part 2) (#6980) @codereport
• Add Ufunc alias look up for appropriate numpy ufunc dispatching (#6973) @VibhuJawa
• Add pytest-xdist to dev environment.yml (#6958) @galipremsagar
• Add Index.set_names api (#6929) @galipremsagar
• Add replace_null API with replace_policy parameter, fixed_width column support (#6907) @isVoid
• Share factorize implementation with Index and cudf module (#6885) @brandon-b-miller
• Implement update() function (#6883) @skirui-source
• Add groupby idxmin, idxmax aggregation (#6856) @karthikeyann
• Implement cudf::reduce for decimal32 and decimal64 (part 1) (#6814) @codereport
• Implement cudf.DateOffset for months (#6775) @brandon-b-miller
• Add Python DecimalColumn (#6715) @shwina
• Add dictionary support to libcudf groupby functions (#6585) @davidwendt

Improvements 🛠️

• Update stale GHA with exemptions & new labels (#7395) @mike-wendt
• Add GHA to mark issues/prs as stale/rotten (#7388) @Ethyling
• Unpin from numpy < 1.20 (#7335) @shwina
• Prepare Changelog for Automation (#7309) @galipremsagar
• Prepare Changelog for Automation (#7272) @ajschmidt8
• Add JNI support for converting Arrow buffers to CUDF ColumnVectors (#7222) @tgravescs
• Add coverage for skiprows and num_rows in parquet reader fuzz testing (#7216) @galipremsagar
• Define and implement more behavior for merging on categorical variables (#7209) @brandon-b-miller
• Add CudfSeriesGroupBy to optimize dask_cudf groupby-mean (#7194) @rjzamora
• Add dictionary column support to rolling_window (#7186) @davidwendt
• Modify the semantics of end pointers in cuIO to match standard library (#7179) @vuule
• Adding unit tests for fixed_point with extremely large scales (#7178) @codereport
• Fast path single column sort (#7167) @davidwendt
• Fix -Werror=sign-compare errors in device code (#7164) @trxcllnt
• Refactor cudf::string_view host and device code (#7159) @davidwendt
• Enable logic for GPU auto-detection in cudfjni (#7155) @gerashegalov
• Java bindings for Fixed-point type support for Parquet (#7153) @razajafri
• Add Java interface for the new API 'explode' (#7151) @firestarman
• Replace offsets with iterators in cuIO utilities and CSV parser (#7150) @vuule
• Add gbenchmarks for reduction aggregations any() and all() (#7129) @davidwendt
• Update JNI for contiguous_split packed results (#7127) @jlowe
• Add JNI and Java bindings for list_contains (#7125) @kuhushukla
• Add Java unit tests for window aggregate 'collect' (#7121) @firestarman
• verify window operations on decimal with java tests (#7120) @sperlingxx
• Adds in JNI support for creating an list column from existing columns (#7112) @revans2
• Build libcudf with -Wall (#7105) @trxcllnt
• Add column_device_view pointers to EncColumnDesc (#7097) @kaatish
• Add pyorc to dev environment (#7085) @galipremsagar
• JNI support for creating struct column from existing columns and fixed bug in struct with no children (#7084) @revans2
• Fastpath single strings column in cudf::sort (#7075) @davidwendt
• Upgrade nvcomp to 1.2.1 (#7069) @rongou
• Refactor ORC ProtobufReader to make it more extendable (#7055) @vuule
• Add Java tests for decimal casts (#7051) @sperlingxx
• Auto-label PRs based on their content (#7044) @jolorunyomi
• Create sort gbenchmark for strings column (#7040) @davidwendt
• Refactor io memory fetches to use hostdevice_vector methods (#7035) @ChrisJar
• Spark Murmur3 hash functionality (#7024) @rwlee
• Fix libcudf strings logic where size_type is used to access INT32 column data (#7020) @davidwendt
• Adding decimal writing support to parquet (#7017) @hyperbolic2346
• Add compression="infer" as default for dask_cudf.read_csv (#7013) @rjzamora
• Correct ORC docstring; other minor cuIO improvements (#7012) @vuule
• Reduce number of hostdevice_vector allocations in parquet reader (#7005) @devavret
• Check output size overflow on strings gather (#6997) @davidwendt
• Improve representation of MultiIndex (#6992) @galipremsagar
• Disable some pragma unroll statements in thrust sort.h (#6982) @davidwendt
• Minor cudf::round internal refactoring (#6976) @codereport
• Add Java bindings for URL conversion (#6972) @jlowe
• Enable strict_decimal_types in parquet reading (#6969) @sperlingxx
• Add in basic support to JNI for logical_cast (#6954) @revans2
• Remove duplicate file array_tests.cpp (#6953) @karthikeyann
• Add null mask fixed_point_column_wrapper constructors (#6951) @codereport
• Update Java bindings version to 0.18-SNAPSHOT (#6949) @jlowe
• Use simplified rmm::exec_policy (#6939) @harrism
• Add null count test for apply_boolean_mask (#6903) @harrism
• Implement DataFrame.quantile for datetime and timedelta data types (#6902) @ChrisJar
• Remove **kwargs from string/categorical methods (#6750) @shwina
• Refactor rolling.cu to reduce compile time (#6512) @mythrocks
• Add static type checking via Mypy (#6381) @shwina
• Update to official libcu++ on Github (#6275) @trxcllnt