💥 Breaking changes

• Disallow mixed string <=> numeric arithmetic in eager (#30071)

🚀 Performance improvements

• Limit the memory of buckets sorted ahead in the sort flush (#30297)
• Make file readers wait for spills while over the memory budget (#30296)
• Count unspilled frames in the memory estimate right away (#30295)
• Simplify more boolean expressions and drop redundant null checks (#30293)
• Wait for spills while over the out-of-core memory budget (#30294)
• Lower the default out-of-core prefetch fraction to 0.5 (#30292)
• Aggregate unique and n_unique in the streaming group-by itself (#30281)
• Return freed memory to the OS right away while out-of-core data is spilled (#30280)
• Gather List(Array) and Array columns without per-row slices (#30278)
• Evaluate the streaming window node out of core (#30282)
• Avoid deep copies when building a DataFrame from flat dataclasses (#30275)
• Sort the window partitions by each order key instead of their row encoding (#30277)
• Scan the haystack for a single needle in is_in (#30276)
• Prefer fixed-width columns when only the row count is needed (#30274)
• Native gather for List arrays (#30019)
• Evaluate windows in filter predicates in the streaming window node (#30272)
• Don't busy-wait in RAYON.block_on (#30259)
• Encode nested Parquet levels directly from the level buffers (#30251)
• Reduce memory of CSV scans on wide rows (#30165)
• Avoid quadratic JSON serialization of nested lists and maps (#30203)
• Skip the gather when exploding lists without nulls (#30234)
• Speed up writing nested Parquet columns (#30245)
• Don't keep whole parquet string dictionaries alive for a few selected rows (#30248)
• Set default spill compression level to 1 (#30237)
• Reuse zstd contexts in compression and avoid memcpys (#30233)
• Remove repeated and scalar ordering keys before the sort rewrites (#30231)
• Remove repeated keys from by's (#30095)
• Keep only one guessed unique key per join order leaf (#30191)
• Don't let extra join keys shrink an estimate once one key is unique (#30190)
• Reduce binary size of asof join with by keys (#30192)
• Reduce binary size of SQL visitors and parallel group-by collect (#30171)
• Push as-of join key filters to the right input (#30123)
• Drop null as-of right keys with a parallel filter before the join node (#30125)
• Keep as-of nearest join state small (#30126)
• Explode lists in group_by aggregations without a per-group apply (#30020)
• Streaming OOC group-by with shuffles (#29911)
• Drop scalar ordering keys in the optimizer (#30063)
• Merge union inputs that scan files of the same kind into one multi-file scan (#30056)
• Use the streaming scalar window for std, var and combined reductions in over (#30066)
• Limit the bytes of local CSV and NDJSON files read at once in multi-file scans (#30055)
• Check the matched flag of join keys in the table entry before the bitset (#30067)
• Track matched build rows of all join tables in a bitset (#30050)
• Add dedicated list gather kernels (#30049)
• Emit unmatched build rows of single-key joins in row order (#30037)
• Use TopK for sorts sliced at a nonzero offset (#29989)
• Add constant folding for more datetime ops (#30016)
• Rewrite the sum of a column plus a literal to a sum and a count of the column (#30011)
• Push predicates through order-keeping columns (#30007)
• Fix dead early exit in coalesce (#30013)
• Count distinct non-null values in SQL with one group-by in the streaming engine (#30009)
• Skip parquet row groups with the running top-k threshold (#30006)
• Keep decompressed plain string pages as the string data buffer (#29984)
• Fix some in-memory filter regressions (#29988)
• Decompress snappy and zstd parquet pages without zeroing the buffer (#29980)
• Speed up str.len_chars (#29972)
• Speed up str.replace for patterns that end in .*$ (#29971)
• Use the Parquet string prefilter for literal str.contains and SQL LIKE (#29953)
• Keep single-chunk output when filtering wide frames in parallel (#29847)
• Add dedicated list slice kernels (#29938)
• Principled execution order of accumulating streaming nodes (#29933)
• Huge speedup creating wide Struct data (#29813)
• Speed up arg_min and arg_max (especially on data with nulls) (#29849)
• Huge reduction in from_rows and from_dicts memory usage during nested value conversion (#29739)
• Safely push down nested struct field filters to Iceberg (#29665)
• Compare Parquet dictionaries of Categorical and Enum columns as strings for == and is_in (#29885)
• Filter Categorical and Enum Parquet columns while decoding (#29882)
• Rewrite sort().first() to min() and single-key sort_by().first() to min_by() (#29860)
• Decode fixed-length binary Parquet decimals directly into i128 (#29866)
• Look up each dictionary value once when importing Arrow dictionaries as Categorical (#29865)
• Reduce requests and raise concurrency for cloud CSV scans (#29863)
• Reduce requests and raise concurrency for cloud NDJSON scans (#29857)
• Track sortedness through joins (#29852)
• Keep sortedness through widening numeric casts (#29851)
• Rewrite sort_by().first() to min_by and limit sorts read with head() (#29831)
• Cache parsed Iceberg metadata for metadata-path scans (#29791)
• Drop memory when Done in streaming asof_join/is_first_distinct (#29783)
• Drop scalar sort_by keys in the optimizer (#29812)
• Parallel CSV chunk analysis and pread default (#29818)
• Hash inline binview values directly from their view (#29820)
• Use iceberg statistics (#29798)
• Reuse Iceberg catalog and cache REST catalog scans (#29790)
• Preserve sortedness of computed join keys (#29782)
• TopK was holding onto too much data (#29784)
• Write CSV temporal values straight into the buffer (#29778)
• Parse strftime format once and reuse buffer in regex replace (#29777)
• Reduce needless allocations in various kernels (#29775)
• Cache http object store (#29757)
• Fetch each record batch group in its own task (#29755)

✨ Enhancements

• Support SQL CREATE TABLE with column definitions in attached Iceberg catalogs (#30260)
• Support SQL CREATE [OR REPLACE] TEMP TABLE (#30256)
• Support recursive SQL CTEs (#30188)
• Writing encrypted Parquet files (#29905)
• Support SQL DROP TABLE [PURGE] on tables of attached catalogs (#30247)
• Add conversion to/from masked numpy arrays (#30232)
• Add overwrite_filter and dynamic partition overwrite to sink_iceberg (#29909)
• Support SQL JOIN ... ON subqueries that read only one input (#30206)
• Support full joins in join_where (#30169)
• Expose fused and nested loop join predicates in the IR visitor (#30176)
• Support LIMIT 1 in correlated SQL scalar subqueries (#30168)
• Support SQL WITH RECURSIVE when no CTE reads itself (#30166)
• Support correlated IN and EXISTS that read both inputs of a SQL join in ON (#30159)
• Support CURRENT_DATE, CURRENT_TIME and CURRENT_TIMESTAMP in SQL (#30144)
• Allow reinterpret between Int128 and Decimal (#30133)
• Add Expr.truncdiv for division rounding toward zero (#30138)
• Support uncorrelated subqueries in SQL JOIN ... ON (#30141)
• Support correlated subqueries in SQL JOIN ... ON and correlated scalar subqueries without an aggregate (#30131)
• Support sinking to Iceberg table with bucket partitioned field (#30091)
• Add create_namespace_if_not_exists to sink_iceberg (#30087)
• Attach Iceberg catalogs to SQLContext via register_catalog (#30113)
• Support OOC kill fraction (#30104)
• Support qualified table names in SQL (#29963)
• Reverse node for streaming engine (#29259)
• Add pl.delete_iceberg (#30032)
• Support named options in SQL read_ipc table function (#30054)
• Support named options in SQL read_parquet table function (#29998)
• Add experimental geoparquet read/write (#29987)
• Accept a list of paths in SQL read_* table functions (#30047)
• Add SQL read_ndjson table function with named options (#29954)
• Support STRUCT and MAP type names in SQL (#29951)
• Support unstable column/schema options in SQL read_csv (#29975)
• Add sampling to KLL approx-quantile sketch (#29424)
• Rust resolver for scan_iceberg (#29753)
• Add REGEXP_REPLACE and DATE_TRUNC to SQL (#29967)
• Add generate_series and range to SQL (#29912)
• Add create_if_not_exists to sink_iceberg (#29908)
• Support named options in SQL read_csv table function (#29917)
• Add query-level IO active time and thread count metrics (#29792)
• Support time-zone-aware timestamps in SQL (#29899)
• Add support for reading encrypted Parquet files (#29606)
• Add SQL ASOF join (#29834)

🐞 Bug fixes

• Compare Array(Struct) rows field by field (#30290)
• Don't revive a dropped out-of-core spill context through a weak reference (#30291)
• Do not read the values stored under null Array rows (#30286)
• Return freed memory to the OS right away while out-of-core data is spilled (#30280)
• Propagate nulls through all nesting levels before row encoding (#30269)
• Add a method to merge finalized approx_quantile sketches deterministically (#30263)
• Use the supertype of both inputs for the cov/corr output dtype (#30262)
• Keep buffered frames spillable while a streaming sort partitions (#30268)
• Respect memory limits of nested cgroups (#30266)
• Correct schema for integer literal divided by Float16/Float32 (#30158)
• Correct str.replace for nested repetitions before .*$ (#30258)
• Allow write_iceberg into Iceberg tables with required columns (#30253)
• Correct operator overloading for reflect ops (#29946)
• Raise on unsupported Avro codecs in read_avro (#30240)
• Support several inputs to anonymous aggregations in the in-memory engine (#30152)
• Stop SQL FROM item aliases from acting as tables (#30207)
• Correct unsigned parquet stats merging (#30199)
• Read Parquet schema in lockstep with arrow metadata hints (#30202)
• Raise on Delta tables with column mapping (#30204)
• Correct comparison with numpy array (#30241)
• Don't keep...

💥 Breaking changes

• Run SQL window functions over grouped rows on the aggregated rows, and evaluate QUALIFY before the projection (#29746)
• Type exact SQL numeric literals as Decimal and truncate SQL %/DIV (#29536)
• Allow deterministic expression plugins to opt into CSE/CSPE (#29428)
• Read Parquet ENUM type as pl.String (#29331)
• More map operations (#29296)
• Deprecate cut/qcut (#29329)

🚀 Performance improvements

• Fix phases ending too soon due to join sampling (#29752)
• Group record batch fetches of remote IPC scans (#29750)
• Mark group-by node as memory intensive pipeline blocker (#29749)
• Don't inline slow OOC memory drift path (#29745)
• Only prefetch on unspill when there is memory headroom (#29701)
• Pushdown filters to scan_lance (#29538)
• Do not materialize equal ScalarColumns in Column::append/extend (#28989)
• Evaluate scalar windows in the streaming window node (#29698)
• Don't materialize scalar columns in DataFrame::estimated_size (#29711)
• Defer cached pread from prefetch to decode for Parquet (#29702)
• Decode IPC scans out of order when order is not observed (#29675)
• IPC metadata suffix fetch (#29692)
• Speed up null tracking in streaming group-by sum, min and max (#29691)
• Cache Iceberg manifest files across scans (#29623)
• Improve pushdown support for fallible Hive predicates (#29594)
• Streamline BytecodeParser method rewriting (#29632)
• Stream from_dicts records straight into column buffers (#29656)
• Read correlated SQL aggregates from the outer join when the subquery repeats it (#29685)
• Emit files unordered for remote IPC files when order not observed (#29678)
• Don't keep input order for order-insensitive windows in all engines (#29680)
• Fix parallelization in top-k reducer (#29684)
• Share one bloom filter between the build threads of a runtime filter (#29677)
• Add streaming (out-of-core) sort (#29657)
• Insert keys that start a run of equal keys into the hot group-by table right away (#29673)
• Prefetch key-row hash table lookups in blocks (#29663)
• Lower count-guarded sums to a sum that is null on empty input (#29668)
• Use single PUT for small cloud uploads (#29603)
• Don't cache plain scans in the streaming engine (#29654)
• Change single-key group-by hash table layout and add prefetching (#29661)
• Use the integer ranges of sampled parquet row groups in filter estimates (#29655)
• Raise HTTP rate-limiter read init default (#29584)
• Change join hash table layout and add prefetching (#29653)
• Add a fast-path for as_list with only a single input (#29592)
• Use one runtime filter builder per thread for a finished sample (#29646)
• Compute decimal addition, subtraction and multiplication in i64 when values fit (#29638)
• Spread decimal sums and means over lanes and check the sum's 38 digits once (#29637)
• Compute decimal addition, subtraction and multiplication without per-row validity (#29634)
• Skip or reuse UDF disassembly in BytecodeParser (#29625)
• Rescale a single decimal operand once in addition and subtraction (#29631)
• Dynamic hot table size in streaming GroupBy (#29629)
• Lower gathering from literal as elementwise (#29605)
• Execute fixed-size rolling windows on streaming engine (#29602)
• Use the finite rule of equi joins to determine build side of semi/anti (#29617)
• Drop the byte limit on runtime filter build sides (#29618)
• Add eviction-free path to GroupedReduction, with lanes (#29613)
• Improve window functions (#29591)
• Push down is_nan/is_not_nan filters to Iceberg (#29579)
• Compute shared group-by agg input subexpressions once (#29574)
• Emit files unordered for remote Parquet files when order not observed (#29581)
• Filter rows by the runtime join key range (#29576)
• Update few-group sums, means and counts in lanes (#29573)
• Loop over 4k arrays in group-by update (#29572)
• Decode parquet scans out of order when order is not observed (#29546)
• Don't always row-encode multi-column group-by (#29570)
• Push down str.starts_with filters to Iceberg (#29545)
• Trace join runtime filters through unions (#29565)
• Fold SQL temporal literals into plain values (#29562)
• Don't rehash stored key on every TotalIndexMap probe (#29561)
• Fuse drops into all filters on streaming engine (#29550)
• Join probe on Arrays directly (#29558)
• Better build side selection in equi-join sampler (#29524)
• Large optimisation for BytecodeParser rewrite/dispatch (#29548)
• Parallelize expressions in in-memory map fallback (#29535)
• Push down != filters to Iceberg (#29455)
• Improve predicate stats (#29495)
• Scale bloom filters from keys seen (#29477)
• Optimize simple like queries (#29459)
• Insert head slice below select(len() <cmp> n) to enable slice pushdown (#29209)
• Parallelize row encoding in the row_encode expression (#29434)
• Degrade outer join optimization (#29432)
• Optionally reorder semi join (#29443)
• Borrow the cached regex instead of cloning it per page (#29422)
• Lower SQL LIKE '%x%' to a literal substring match (#29431)
• Optimize is_in expression (#29425)
• Pushdown bloom filters in probe side (#29423)
• Narrow the decimal rescale to 64 bits when the value fits (#29396)
• Use a thread-local copy of a pushed-down regex predicate (#29411)
• Sample anti-join build side (#29416)
• Improve performance importing from arrow (#29412)
• Sample table size to determine build side in semi joins (#29375)
• Optimize row-encoding (#29405)
• Order pushed parquet predicate columns by measured selectivity (#29397)
• Coerce float literals to decimal instead of casting the column (#29395)
• Fix OOM on TPCH SQL and fix fuzzing errors (#29389)
• Restrict correlated SQL aggregates to requested keys (#29383)
• Prepare Parquet scans for row-group splitting in Polars Cloud (#29295)
• Skip row groups by join runtime ranges without a statistics frame (#29370)
• Reduce copy in scan_lines (#29310)
• Increase HTTP read rate-limit default (#29363)
• Evaluate a pushed parquet predicate sequentially per conjuct (#29352)
• Disable system certificates for CloudScheme::Http sources (#29284)
• Reduce rechunk in sort_in_place (#29343)
• Dynamic predicates for hash joins (#29312)
• Use HTTP suffix range for Parquet size and footer (#29308)
• Derive predicates from join conditions (#29304)
• Lower uncorrelated subqueries to semi joins and push semi/anti joins below inner joins (#29289)
• Make leaf name iterator unique (#29291)
• Don't clone the full frame per arm in when/then/otherwise (#29258)
• Push inner joins before outer joins and rewrite left-join-is-null to anti join (#29277)
• Use stats to decide cross join buffering side (#29270)
• Improve cache-removal and join-order cost estimates (#29263)
• Improve CSPE cost evaluation (#29250)
• Fuse group-by pre-select into node after partition (#29251)
• Inline hot small functions (#29244)
• Fix plan-time regressions in projection pushdown for wide frames (#28724)
• Rechunk before selecting in group-by pre-select (#29219)
• Reuse Iceberg data file sizes (#29063)

✨ Enhancements

• Python Polars 2.0 (#29723)
• Enable OOC by default with 80% of available RAM as threshold (#29741)
• Support window frames in SQL FIRST_VALUE and LAST_VALUE, and add NTH_VALUE and a LAG/LEAD default (#29740)
• Set default OOC disk budget to 64 GB (#29734)
• Add POLARS_OOMKILL_THRESHOLD_MB (#29735)
• Improve estimated DataFrame memory usage (#29712)
• Extend pipe_with_dtype for multiple expressions (#29676)
• Attribute physical nodes to IR nodes (#29522)
• Make approx_quantile sketch states mergeable across processes (#29660)
• Add unstable scan_lance (#29413)
• New Expression and function: pipe_with_dtype (#29547)
• Resolve is_in and Map lookup coercion from dtypes alone (#29487)
• Cast the needle of is_in and Map lookups exactly or not at all (#29486)
• Support Map in JSON and NDJSON reading and writing (#29478)
• Add scan_external_reader (#29232)
• Add struct.eval (#29454)
• Improve BytecodeParser UDF variable resolution (#29553)
• Type exact SQL numeric literals as Decimal and truncate SQL %/DIV (#29536)
• Make Iceberg sink commits idempotent across re-executions (#29512)
• Allow deterministic expression plugins to opt into CSE/CSPE (#29428)
• Improve cloud object_store IO error types and messages (#29471)
• Add erf(c) function (#29501)
• Update BytecodeParser for Python 3.15 (#29491)
• Expose the registered source as scan_fn.io_source (#28897)
• Support selectors in join keys (#29233)
• Honor Iceberg sort orders in native sinks (#29318)
• Add APPROX_QUANTILE to the SQL frontend (#29288)
• Add support for approx_quantile in the streaming engine (#29237)
• Read Parquet ENUM type as pl.String (#29331)
• Expose more scan_iceberg/delta-related attributes in the visitor for cudf_polars (#29297)
• More map operations (#29296)
• Binning functions (#28888)
• Support collect and collect_batches using RemoteEngine (#28914)
• Support GROUP BY GROUPING SETS, ROLLUP, CUBE and GROUPING() (#29278)
• Fix tpch SQL issues (#29269)
• Fuse filters in (inner) join operation (#29218)
• Add in-memory support for approximate quantile (#29206)
• Disable casts from String to Time (#29215)

🐞 Bug fixes

• Find SQL aggregates by their function name, and raise on nested aggregate calls (#29751)
• Run SQL window functions over grouped rows on the aggregated rows, and evaluate QUALIFY before the projection (#29746)
• Match categories added after is_in prepares a string haystack (#29744)
• Give tied rows the same running aggregate in SQL windows, and support more window frames (#29736)
• Fix scan_lance CI error (#29737)
• Rank NULLs and ties in SQL window functions, and add PERCENT_RANK, CUME_DIST and NTILE (#29729)
• Read from database without requiring SQLAlchemy asyncio extra (#29713)
• Don't slice the input of a select that has a window expression (#29725)
• Fix named SQL windows and raise for window shapes that gave wrong results (#29720)
• Preserve projections ...

💥 Breaking changes

• Read Parquet ENUM type as pl.String (#29331)
• More map operations (#29296)
• Deprecate cut/qcut (#29329)
• Remove legacy POLARS_STREAMING_CHUNK_SIZE (#29046)
• Introduce the Map dtype (#28984)
• Update behavior of DataFrame/LazyFrame functions on 0-width input (#29099)

🚀 Performance improvements

• Order pushed parquet predicate columns by measured selectivity (#29397)
• Coerce float literals to decimal instead of casting the column (#29395)
• Fix OOM on TPCH SQL and fix fuzzing errors (#29389)
• Restrict correlated SQL aggregates to requested keys (#29383)
• Prepare Parquet scans for row-group splitting in Polars Cloud (#29295)
• Skip row groups by join runtime ranges without a statistics frame (#29370)
• Reduce copy in scan_lines (#29310)
• Increase HTTP read rate-limit default (#29363)
• Evaluate a pushed parquet predicate sequentially per conjuct (#29352)
• Disable system certificates for CloudScheme::Http sources (#29284)
• Reduce rechunk in sort_in_place (#29343)
• Dynamic predicates for hash joins (#29312)
• Use HTTP suffix range for Parquet size and footer (#29308)
• Derive predicates from join conditions (#29304)
• Lower uncorrelated subqueries to semi joins and push semi/anti joins below inner joins (#29289)
• Make leaf name iterator unique (#29291)
• Don't clone the full frame per arm in when/then/otherwise (#29258)
• Push inner joins before outer joins and rewrite left-join-is-null to anti join (#29277)
• Use stats to decide cross join buffering side (#29270)
• Improve cache-removal and join-order cost estimates (#29263)
• Improve CSPE cost evaluation (#29250)
• Fuse group-by pre-select into node after partition (#29251)
• Inline hot small functions (#29244)
• Fix plan-time regressions in projection pushdown for wide frames (#28724)
• Rechunk before selecting in group-by pre-select (#29219)
• Reuse Iceberg data file sizes (#29063)
• Avoid gather for >= 75% cold keys in streaming group-by (#29217)
• Elide memset on pread for FileByteSource (#29162)
• Add prefetching to OOC (#29081)
• Push more predicates past caches (#29182)
• Prevent cache trashing in row encoding for fixed width types (#29175)
• Improve group-by cardinality estimates (#29174)
• Split join clusters across filters and bound key domains by value range (#29166)
• Make file read concurrency semaphore global (#29163)
• Skip redundant output validity construction in all-valid arr.dot (#29115)
• Default posix_fadv to Normal (#29157)
• Avoid a full fsync per file when writing Parquet (#29108)
• Replace mmap with file I/O for parquet scan (#29091)
• Use adaptive concurrency for head requests (#29131)
• Improve join-reordering (#29092)

✨ Enhancements

• Expose the registered source as scan_fn.io_source (#28897)
• Support selectors in join keys (#29233)
• Honor Iceberg sort orders in native sinks (#29318)
• Add APPROX_QUANTILE to the SQL frontend (#29288)
• Add support for approx_quantile in the streaming engine (#29237)
• Read Parquet ENUM type as pl.String (#29331)
• Expose more scan_iceberg/delta-related attributes in the visitor for cudf_polars (#29297)
• More map operations (#29296)
• Binning functions (#28888)
• Support collect and collect_batches using RemoteEngine (#28914)
• Support GROUP BY GROUPING SETS, ROLLUP, CUBE and GROUPING() (#29278)
• Fix tpch SQL issues (#29269)
• Fuse filters in (inner) join operation (#29218)
• Add in-memory support for approximate quantile (#29206)
• Disable casts from String to Time (#29215)
• Add organization to Config.enable_monitoring (#29221)
• Add a workspace argument to Config.enable_monitoring (#29196)
• Remove legacy POLARS_STREAMING_CHUNK_SIZE (#29046)
• Add LazyFrame resolver API (#29003)
• Support incremental append Iceberg scans (#28820)
• Support date/integer arithmetic and decimal non-equi join comparisons (#29156)
• Update documentation analytics implementation (#29127)
• Introduce the Map dtype (#28984)
• Update behavior of DataFrame/LazyFrame functions on 0-width input (#29099)

🐞 Bug fixes

• Fix OOM on TPCH SQL and fix fuzzing errors (#29389)
• Size row-index table statistics from the statistics frame (#29381)
• Preserve categories object in pyo3-polars (#29385)
• Strip the leading slash from Windows Delta table roots (#29386)
• Isolate expanded Python dataset scans (#29378)
• Make Iceberg bucket sort keys serializable (#29376)
• Apply "schema_overrides" in read_database for Arrow-based drivers (#29273)
• Remove duplicated word in rate-limit comment (#29372)
• Check whether Datetime is monotonically increasing dynamically (#29293)
• Keep input order of unmatched build rows in ordered streaming equi join (#29371)
• Unaliased constants in SQL SELECT with GROUP BY (#29367)
• Consistent Date and Decimal means between the streaming and in-memory engines (#29359)
• Respect string statistics for enum columns during parquet scanning (#29366)
• Support selectors properly in DataFrame n_unique (#29360)
• Decimal Parquet statistics for decimal/i128/f16 (#29350)
• Early check for converting integer map keys (#29348)
• Lowering for input-independent filter (#29340)
• Correlation of constant column returning non-NaN for larger inputs (#29319)
• Incorrect height in multi-input GroupBy (#29332)
• Fix panic in scan_iceberg for snapshot_id before a schema change (#28895)
• Resolve arithmetic Struct supertypes per-field (#29261)
• Fix comparison expression method comment (#29257)
• Don't panic on an empty or null quantile expression input (#29240)
• Detect list-valued quantile literals in approx_quantile auto (#29236)
• Various map issues (#29147)
• Rolling quantile should respect window trimming (#29200)
• Ensure ignored columns are excluded from dtype Wildcard selector (#29220)
• Include the library path in the plugin dlopen error message (#29213)
• Respect Parquet schema when reading Int96 timestamps (#29208)
• Wrap IoError in PathIoError such that callers can extract untruncated path (#29128)
• Slice on Series with negative index beyond length (#29191)
• Fix OOB access due to empty chunks (#29177)
• Compare struct AnyValues through their field dtypes (#29185)
• Improve group-by cardinality estimates (#29174)
• Preserve scalar arrays in arr.dot dispatch (#29000)
• Empty array collect missing dtype in join (#29095)
• Apply the OVER clause to multi-argument aggregates (#29160)
• Respect NULLS FIRST/LAST in a window's ORDER BY (#29159)
• Resolve relation aliases declared inside a parenthesized JOIN (#29158)
• Fix a DataFrame construction race (and generator data loss) (#29132)
• Properly compute null count in parquet statistics for list of categorical/enum (#29140)
• Address read_database Oracle regression, following introduction of Arrow fast-path (#29142)
• Synchronize PR label matchers (#29144)
• Unblock Python thread during collect_all_async (#29097)
• Match engine output dtype in planner for Decimal true division with integers (#29122)
• Error instead of segfault for exp/log1p on non-numeric dtypes (#29112)
• Prevent panic in offset_by when target date is out-of-range (#29059)
• Incorrect broadcast height min/max_horizontal for scalar inputs (#29083)
• Proper seq id relabeling before distributing (#29060)

📖 Documentation

• Clarify that ambiguous parameter refers to DST transitions (#28873)
• Document gzip/zstd compression for read_csv and scan_csv (#29387)
• Add LazyFrameResolver to reference guide (#29379)
• Add user-guide for new enable_monitoring feature (#29358)
• Improve join_where engine tag (#29234)
• Add 2 to the version switcher dropdown (#29194)
• Show more information in engine tags (#29154)
• Engine tags for is_empty/ has_nulls (#29152)
• More engine tags (#29148)
• Fix misleading reinterpret() docstring (#29075)

📦 Build system

• Add a fast-release profile without LTO (#29168)

🛠️ Other improvements

• Add dymanicpredicates to preferred build sides (#29335)
• Deprecate cut/qcut (#29329)
• Mark test as slow (#29336)
• Bump maturin (#29282)
• Bump object_store crate to 0.14.2 (#29317)
• Update rustls dependency to version 0.23.45 (#29303)
• Bump build deps used in ARM64 Windows release pipeline (#29280)
• Fix the stalling test_fused_many_morsels_and_skew test (#29290)
• Use SpillFrames in DataFrameSearchBuffers (#29207)
• More obvious MapChunked storage handling (#29248)
• Centralize hoisted aggregate bookkeeping and clarify grouping predicates (#29287)
• Update analytics endpoint config (#29222)
• Add a blanket lf.collect().schema == lf.collect_schema() check (#29224)
• Add expand_paths parameter to toggle path expansion (#29210)
• Remove auto-streaming jobs (#29214)
• Bump object_store for new DnsResolver trait (#29145)
• The in-memory engine is no longer the default in the docstrings (#29137)
• Test list-of-structs in map_elements (#24925)
• Update existing comment instead of new comment for file size on PR (#29134)
• Output stdout/stderr of crashed pytest-xdist workers (#29094)
• Remove batched_reader.py (#29098)
• Update test for latest pyiceberg (#29090)

Thank you to all our contributors for making this release possible!
@0guban0v, @ATL2001, @Aidavdw, @AlessandroKuz, @BitWeaverDev, @DeflateAwning, @EndPositive, @Kevin-Patyk, @MarcoGorelli, @SatvikMishra08, @aarushkandukoori, @abokhalill, @alexander-beedie, @atharva7905k, @ayushh0110, @borchero, @carnarez, @dancsi, @dsprenkels, @freundTech, @fsimkovic, @jonasdedden, @kafka1991, @kdn36, @lun3x, @madsbk, @matthewbayer, @mikhail5555, @mroeschke, @nameexhaustion, @orlp, @r-brink and @ritchie46

🛠️ Other improvements

• Backport 1.44.2 (#29216)

Thank you to all our contributors for making this release possible!
@EndPositive, @dsprenkels, @kdn36, @lun3x, @nameexhaustion and @orlp

💥 Breaking changes

• Set the default engine for SQL to the streaming engine (#28973)

🚀 Performance improvements

• Reuse native metadata for Iceberg sinks (#29062)
• SQL exists predicate pushdown before subqueries (#29078)
• Collect primitive group-by aggregations into single chunk (#28825)
• Use cost information to determine whether to keep cached nodes (#29042)
• Use scan cardinality in build side if sampling is exhausted (#29040)

✨ Enhancements

• Defer SQL resolving until we convert to IR (#29077)
• Expose Iceberg sink writer options (#29065)
• Support partitioned Iceberg sinks (#28823)
• Expose fixed-array inner product in SQL (#29033)
• Add strip_prefix and strip_suffix to expression names (#29041)
• Use scan information in join reordering (#29038)
• Add cardinality information (#29024)
• Allow customizing explain output for debugging custom io sources (#23978)
• Add more expression properties to meta namespace (#28091)
• Improve SQL coverage (#29010)
• Improve SQL coverage (#29006)
• Add Join reordering. (#28985)
• Merge 2.0 into main (#28982)
• Set the default engine for SQL to the streaming engine (#28973)

🐞 Bug fixes

• Don't keep incrementing morsel id in MergeSortedNode pass-through (#29055)
• Ensure show_graph shows physical plan for auto engine (#29011)
• Assign SQL JOIN literal comparisons to the correct input (#28701)
• Make distributor linearizer capacity consistent (#29057)
• Correct peak visitors, dictionary bounds, and Date feature gating (#29031)
• Keep extension type schema consistent (#29039)
• Fix Series.sample order when with_replacement=True and shuffle=False (#28990)
• Reduce memory in multi_scan pipeline PostApplyExtraOps (#29049)
• Fix SO in rayon caused by join_where (#29051)
• Clarify GPU installation guidance (#29037)
• Remove POLARS_AUTO_STRUCTIFY env var backdoor (#29032)
• Ensure metrics are flushed between phases and before logging (#29014)
• SQL parse a typed DATE literal instead of casting it (#29007)
• Fix parquet decode of plain pages in dictionary column (#29001)
• Reserve fixed-size-list child capacity (#28980)
• Fix SQL casts (#28986)
• Fix incorrect condition in combine_validities_and_many and add test (#28909)
• Give sink_batches lazy: Literal[False] overload a default (#28951)

📖 Documentation

• Update 2.0.0-rc1 migration guide with latest changes (#28983)
• Fix invalid output in DataFrame.sample example (#28998)

🛠️ Other improvements

• Bump rust toolchain (#29080)
• Increase rustc stack size (#29076)
• Log pytest worker crashes and disable restarting (#29058)
• Replace FileInfo row_estimation tuple with typed ScanStats (#29023)
• Use an if for cfg(debug_assertions) to fix the benchmark job (#29002)
• Remove 2.0 branch from ci-tested branches (#28981)
• Skip tests that are currently failing on windows (#28962)

Thank you to all our contributors for making this release possible!
@0guban0v, @0xC61, @Aniket-a14, @LarryHu0217, @MatteoPossamai, @NeejWeej, @TNieuwdorp, @WaterWhisperer, @adamreeve, @dsprenkels, @jonasdedden, @kdn36, @math-hiyoko, @matthewbayer, @nameexhaustion, @orlp, @ritchie46, @severinh and @sivakumar-mahalingam

Thank you to all our contributors for making this release possible!
@Kevin-Patyk, @henrytsanford, @jonasdedden, @orlp and @ritchie46

⚠️ Deprecations

• Deprecate rechunk parameter for all read/scan functions (#28063)
• Deprecate Expr.rechunk() (#28692)
• Deprecate struct.rename_fields() with an incorrect number of fields (#28672)

🚀 Performance improvements

• Add private env var toggle for HTTP rate limit (#28882)
• Relax default CloudRetryConfig for rate limit stability (#28885)
• Elide generic cross join on subquery decorrelation in equality predicates (#28876)
• cache CTE's in SQL layer (#28864)
• Allow CSPE if manual caches are set (#28859)
• Lower unqualified join predicates to inner joins in SQL (#28854)
• Rechunk mask for DataFrame filter (#28762)
• Improve performance of when/then/otherwise by masking out unevaluated elements (#28498)
• Drop unused projections in filter on streaming engine (#28713)
• Retain Parquet Partial metadata on filter (#28737)

✨ Enhancements

• Support integer fixed-array dot products (#28829)
• SQL correlated in (#28927)
• Support more join_types in join_where (#28880)
• Support Iceberg schema evolution (#28794)
• SQL conformance (#28494)
• Introduce RemoteEngine and a common base class for all engines (#28800)
• Support Iceberg table with V3 deletion vectors in native scan_iceberg (#28772)
• Support Iceberg snapshot properties (#28793)
• Expose sinked_paths_callback on sink_parquet as unstable parameter (#28814)
• Add infer_schema_files to CSV inference hint (#28809)
• Add native fixed-array dot (#28504)
• Export query metrics to polars_cloud (#28757)
• Support Iceberg object storage paths (#28634)
• More CSEE simplification (#28731)
• Improve error in Series constructor with name in context (#28743)
• Add adaptive HTTP rate-limiter for cloud IO (#28591)
• Add struct.drop() (#28666)
• Improve error message when CSV name de-duplication fails (#28658)
• Always keep first metadata per source for Parquet (#28661)
• Improve plan-time row estimates for multi-file parquet scans (#28380)
• Expose array and plugin function views in Python visitor (#28635)

🐞 Bug fixes

• SQL handle quantified comparisons against a subquery (#28929)
• Fix SQL subquery qualified lowering and cache row-index (#28926)
• Clippy-stable failures (#28919)
• Use uuidv7 for cloud observed queries (#28910)
• Unsoundness in AnyValue::into_static for structs (#28889)
• Invalidate suborders on projection (#28866)
• Ensure SQL function registry is available in isolated subqueries (#28881)
• Handle null in Expr.is_not_nan (#28883)
• Ensure eager unpivot column selection aligns with the lazy engine (#28846)
• Fix assertion error / incorrect data load from parquet written by fastparquet (#28656)
• Fix projection pushdown incorrect select() height (#28751)
• Restore monitoring as an engine-level parameter (#28821)
• Bincode serialization of IR hints (#28837)
• Retain datetime inference across CSV fallback (#28663)
• Avoid chunk fragmentation on bool agg min and max (#28789)
• Merge join with coalesce and empty suffix (#28799)
• Wrong function name call in test (#28801)
• Preserve row mapping in nested over expressions (#28767)
• Restore CI compatibility with NumPy 2.5.2 (#28782)
• Do not deduplicate inherently nondeterministic plan nodes (#28768)
• Fix OOC spilling of categoricals (#28761)
• Correct partitionable filter handling for pivot (#28749)
• Small typo in docstring (#28763)
• Avoid chunk fragmentation on bool agg any and all (#28754)
• Ignore nans in (min|max)_horizontal (#28710)
• Correct function display for str.replace_all (#28742)
• Exclude debug tests from nodebug streaming run (#28747)
• Convert predicate series dtype during prefiltered parquet reading (#28711)
• Do not remove nested caches when performing predicate pushdown past a cache node (#28740)
• Correct handling of nulls at the start of business day functions (#28703)
• Do not panic when exceeding Parquet metadata scan cache (#28721)
• Remove cryptographic hashing from CSPE (#28716)
• Unsoundness in rayon block_on (#28709)
• Check for (shallow) IR node equality on top of hashing in CSPE (#28506)
• Don't hand IO plugins a predicate they cannot evaluate (#28643)
• Raise on overflow in Decimal sum instead of silently wrapping (#28688)
• Preserve nulls when importing Arrow maps (#28680)
• Propagate null by column values in rolling_*_by (#27367)
• Fix self-referencing field in struct.with_fields with over (#28678)
• Fix Arrow buffer offset for Utf8 and Binary (#28662)
• Clamp group-by slice offset (#28579)
• Release the GIL while resolving the schema in __arrow_c_stream__ (#28642)
• Fix data corruption on Series from nested Arrow LargeList (#28632)

📖 Documentation

• Interlink join docstrings (#28907)
• Migration guide for 2.0 release (#28788)
• Clarify read_database_uri requirements for SQLAlchemy (#28366)
• Update engine tags (#28852)
• Clarify "that that side" comment in asof_join (#28847)
• Update mage.ai documentation link (#28813)
• Add engine tags (#28708)
• Document that arg_extremum functions return any index on ties (#28691)
• Fix Polars Cloud API reference link (#28693)

🛠️ Other improvements

• Bump runtime toolchains (#28924)
• Add min-publish-age for cargo (#28906)
• Tighten join invariants DSL (#28913)
• Bump Rust toolchain (#28900)
• Ensure that predicates are pushed down to the scans (#28857)
• Clarify "that that side" comment in asof_join (#28847)
• Restore monitoring as an engine-level parameter (#28821)
• Remove workaround for inconsistent CSE (#28834)
• Introduce RemoteEngine and a common base class for all engines (#28800)
• Add row count and file byte size to sinked paths callback (#28522)
• Use canonical expression IDs in CSEE (#28786)
• Enforce 100% type coverage in CI with Pyrefly (#28795)
• Attribute annotations for CredentialProviderAWS and CredentialProviderAzure (#28790)
• Attribute annotations for ScanCastOptions (#27906)
• Disable credentials in upload chunk size tests (#28745)
• Improve backtrace path formatting (#28732)
• Exclude debug tests from nodebug streaming run (#28747)
• Mark test_grouped_agg_parametric as slow (and add param ids) (#28715)
• Fix first expect in test_group_by_arg_max_boolean_26978 (#28690)
• Fix the name of struct.drop() in rename_fields() deprecation message (#28687)
• Add dist=loadgroup to the pytest config (#28676)
• Enable a lot of may_fail_auto_streaming tests (#28675)
• Re-enable test_extension() for streaming engine (#28611)
• Update test_hive_join_rewrite_semi_join test to work with streaming engine (#28610)

Thank you to all our contributors for making this release possible!
@0guban0v, @JakubValtar, @Joosboy, @Kevin-Patyk, @MatteoPossamai, @NicoOhR, @TNieuwdorp, @VedantMadane, @aarushkandukoori, @alexander-beedie, @azimafroozeh, @borchero, @carnarez, @dancsi, @dependabot[bot], @dsprenkels, @gautamvarmadatla, @jonasdedden, @jorenham, @kdn36, @lzcmian, @malhotrashivam, @matthewbayer, @mikhail5555, @nameexhaustion, @orlp, @ritchie46, @subotac and dependabot[bot]

✨ Enhancements

• Add adaptive HTTP rate-limiter for cloud IO (#28591)

🐞 Bug fixes

• Unsoundness in rayon block_on (#28709)
• Check for (shallow) IR node equality on top of hashing in CSPE (#28506)

📖 Documentation

• Document that arg_extremum functions return any index on ties (#28691)

Thank you to all our contributors for making this release possible!
@dancsi, @dsprenkels, @kdn36, @orlp and @ritchie46

This Releases' DSL matches Python 1.43.2.

🚀 Performance improvements

• Pushdown len() to concat/union inputs (#28570)
• Optimize not(bool_f) to not_bool_f (#28474)
• Split multiplexers that directly scan from in-memory DataFrame (#28376)
• Make DNS cache global (#28352)
• Do not remove cache if predicates not pushed to all inputs (#28341)
• Environment variable for logging slow DNS lookup (#28211)
• Pre-partition on left, right and semi joins on hive partitioned data (#28374)
• Rewrite inner joins on hive partitioned data to a union of partitions filtered joins (#28327)
• Tighten redundant comparisons and propagate filter constraints (#27999)
• Canonicalize predicates (#28212)
• Remove excess memory copy in streaming IPC sink (#28141)
• Parallelize scan_iceberg resolve (#28168)
• Chunk-aware morsel splitting on single-file IO sink (#27950)
• Don't allocate for full_null() with small lengths (#28181)
• Use monotonic deque for rolling min_by/max_by (O(n)) (#27436)
• Add a sampled resolve mode for multi-file parquet metadata (#28111)
• Speed up small dtype series sums with a upcast sum kernel (#27958)
• Don't block on path expansion (#28073)
• Add bytes-based concurrency control for cloud IO (#27924)
• Stop flushing multiplexer on phase change (#28013)
• Prevent empty chunks from triggering copy in rechunk (#27953)
• Improve performance of struct unnest inside list eval on streaming (#27905)

✨ Enhancements

• Add struct.drop() (#28666)
• Improve error message when CSV name de-duplication fails (#28658)
• Always keep first metadata per source for Parquet (#28661)
• Improve plan-time row estimates for multi-file parquet scans (#28380)
• Serialize and deserialize SinkTypeIR::Partitioned (#28112)
• Add infer_schema_files parameter to scan_csv (#28440)
• Support reading IEEE 754 total order Parquet column order (#27896)
• Expose more Expr nodes for cudf_polars (pt 2) (#28404)
• Allow callback sinks on cloud (#28458)
• Pre-partition group-by on hive keys (#28444)
• Add ewm_sum and ewm_sum_by #28151 (#28215)
• Serve stale records from object_store DNS cache (#28256)
• Expose more expr nodes for cudf-polars (#28117)
• Make partition_hive an opt flag (#28345)
• When displaying IRExprs, only add parentheses when needed for disambiguation (#28319)
• Show only differing dtypes in assert_frame_equal error (#27816)
• Add Clone to SpillFrame/Token (#28302)
• Add Series.degrees/radians and clarify trig functions use radians (#22961)
• Merge sorted with multikey (#28067)
• Add list expression which consistently packs elements together into new List type (#27990)
• Construct pyarrow predicates via PyO3 instead of eval str (#27271)
• Optimize joins with redundant equi-join keys (#28017)
• Implement missing datetime options for CastColumnsPolicy (#28084)
• Add Expr.cat.to and Expr.cat.physical (#28096)
• Add POLARS_OOC_DISK_BUDGET_MB (#28045)
• Close ResourceWarning leaks in database tests (#28066)
• Expose IRFunctionExpr::Fused in the python node visitor (#27889)
• Deprecate casts from string to temporal dtypes (#28056)
• Add naive out-of-core spilling to Polars (#27998)
• Add experimental strict mode (#28023)
• Optimize non-negative len and null_count comparisons (#28002)
• Optimize len and null_count comparisons (#27727)
• Support SQL's implicit JOIN syntax (#27890)
• Sample from bivariate distribution for spill context Thompson sampling (#27973)
• Add Expr.is_sorted (#26708)
• Add suggestions in wrong api usage or mismatched column names (#27954)
• Add external object_store support for non-native schemes (#27871)
• Skip Delta files and parquet row groups using per-field struct statistics (#27887)
• Add re-registration of OOC SpillTokens (#27909)
• Improve IR sortedness detection for with_row_index and explode (#27875)
• Add DataFrame.is_sorted() (#27870)

🐞 Bug fixes

• Don't hand IO plugins a predicate they cannot evaluate (#28643)
• Don't hang or crash on sqrt/cbrt/pct_change/ewm_* with a Struct column (#28696)
• Raise on overflow in Decimal sum instead of silently wrapping (#28688)
• Preserve nulls when importing Arrow maps (#28680)
• Propagate null by column values in rolling_*_by (#27367)
• Fix self-referencing field in struct.with_fields with over (#28678)
• Fix Arrow buffer offset for Utf8 and Binary (#28662)
• Clamp group-by slice offset (#28579)
• Ensure categorical fill_null(strategy="min"/"max") uses lexical min/max (#28636)
• Release the GIL while resolving the schema in __arrow_c_stream__ (#28642)
• Fix data corruption on Series from nested Arrow LargeList (#28632)
• Properly propagate enum metadata for iceberg column mapping (#28580)
• Correctly write parquet field IDs for enums and categoricals (#28581)
• Fix arrow C interop binview offset (#28623)
• Fix duplicate hive values in hive pre-partition rewrite (#28621)
• Double-counted offset for Arrow export of sliced Series(Array) (#28602)
• Struct/List/Array equality handling in sort and join (#28601)
• Use try_new in StructArray construction in polars-json (#27489)
• Raise ComputeError instead of panicking in repeat_by when output exceeds IdxSize::MAX (#27892)
• Run type coercion pass on pivot's internally generated group_by (#27897)
• More careful slice pushdown into joins (#28578)
• Preserve ordering in sliced unions (#28576)
• Drop input sortedness when casting to a string (#28574)
• Clear sortedness flags in StringChunked substring kernels (#28573)
• Bad mask handling when reading optional parquet column (#28547)
• Any operation on Unknown(Int) and Unknown(Float) should result in Unknown(Float) (#28545)
• Flip nulls_last after Expr.reverse() (#28572)
• Fix high blocking thread use in sink_parquet with async local path (#28543)
• Serialize LazyFrames backed by bytes (#28568)
• Release GIL in SQLContext.execute() (#28549)
• Propagate nulls_last in function_expr_sortedness (#28544)
• Incorrect slicing when a join requires sorting (#28541)
• Fix panic on self join of scan_delta / scan_iceberg (#28468)
• Decrement ParkGroup worker count when worker exits (#28492)
• Add missing Send bounds in Connector (#28497)
• Fix UB on first/last_non_null with empty chunk (#28495)
• Do not CSE non-column height expr on streaming engine (#28480)
• Propagate adjusted sortedness through Gather (#28493)
• Deduplicate the expression equality checks (#28483)
• Address 3VL issue with SQL NOT IN interaction with NULL values and joins (#28484)
• Use total comparison in Expr literal values (#28482)
• Ensure SQL SUM and CORR aggregates return NULL for all-null inputs, add TOTAL (#28475)
• Share null_count_dtype helper between Delta and Iceberg, fixing SchemaError (#28479)
• Remove non-output columns from the equi-join and semi/anti-join operators (#28446)
• Fix dropped slice on multiple unions (#28477)
• Fix in-memory engine incorrect slice on maintain order join (#28478)
• Check join schema by position (#28455)
• Block predicate pushdown past overwritten window keys (#28429)
• Avoid panic when union slice skips all rows (#28420)
• Solve panic in dt.replace when there were multiple chunks (#28437)
• Propagate is_scalar from the input to the output of .sort() and .sort_by() (#28438)
• Insert missing coercions from Unknown(_) in list/array arithmetic (#28411)
• Resolve CSV column names overwrite in DSL->IR conversion (#28383)
• Avoid IEJoin rewrite for Categorical comparisons (#28427)
• Do not rewrite sort().reverse() to sort(descending=True) when maintain_order=True (#28403)
• Propagate bigidx to polars-plan from polars (#28396)
• Ensure BinaryView offset+len does not exceed i32::MAX where possible (#28048)
• Invalid offset in strptime (#28388)
• Incorrect schema type for decimal <-> primitive division (#28373)
• Panic in in-memory CSEE handling (#28371)
• Apply same type coercion to IsBetween as binary comparisons (#28300)
• Fix offset in arrow ffi export of sliced struct arrays (#28369)
• Fix cross filter not applied with sink and CSE (#28297)
• Fix panic on projection pushdown with caches (#28280)
• Fix write_json() null values in Array columns being written incorrectly as null (#28330)
• Fix EntityTooSmall on sink_ipc to S3 (#28255)
• Raise error instead of silent wrapping for select(len()) (#28355)
• Float16 groupby aggregates (#28361)
• Respect lexical ordering of Categorical in top_k/bottom_k (#28359)
• Support dtype-list schema overrides in scan_csv (#28226)
• Resolve unknown type in fused multiply add (#28321)
• Honor aws_checksum_algorithm when provided (#28328)
• Fix regression in sourcing HF_TOKEN (#28317)
• Raise on addition/subtraction between temporal and non-temporal Series (#28266)
• Rewrite with_columns on empty df to select during DSL -> IR (#28298)
• Fix sink deadlock regression (#28296)
• Avoid panic when consumer of vertical concat is done (#28272)
• Ensure predicate simplification is deterministically ordered (#28269)
• Don't attribute untimed execution to optimization in profile (#28273)
• Harden IPC mmap API (#28258)
• Classify S3 region request failures as IO errors (#28225)
• Incorrect inner dtype in ArrayChunked::from_aligned_values (#28249)
• Unsoundness in arg_sort_ascending (#28245)
• Add column length check to row encoding (#28248)
• Raise on implode of Object dtype instead of creating invalid List(Object) (#28246)
• Don't panic in qcut on degenerate float input (all-NaN, infinite, include_breaks) (#28220)
• Fix streaming Strptime feature flags (#28242)
• Return null not 0 for the first unbiased ewm_var/ewm_std value (#28235)
• Use after free in file cache (#28236)
• Incorrect length calculation in parallel hashmap (#28227)
• Avoid slice pushdown panic on shared cache inputs (#28157)
• Incorrect dtype for Unknown rig...

⚠️ Deprecations

• Deprecate casts from Categorical to integer dtypes (#28525)
• Deprecate not setting the plan_stage argument in show_graph() (#28391)

🚀 Performance improvements

• Pushdown len() to concat/union inputs (#28570)

✨ Enhancements

• Issue FutureWarning on using from_arrow of ArrowStreamExportable (#28442)
• Add infer_schema_files parameter to scan_csv (#28440)

🐞 Bug fixes

• Properly propagate enum metadata for iceberg column mapping (#28580)
• Correctly write parquet field IDs for enums and categoricals (#28581)
• Fix arrow C interop binview offset (#28623)
• Fix duplicate hive values in hive pre-partition rewrite (#28621)
• Double-counted offset for Arrow export of sliced Series(Array) (#28602)
• Struct/List/Array equality handling in sort and join (#28601)
• More careful slice pushdown into joins (#28578)
• Preserve ordering in sliced unions (#28576)
• Drop input sortedness when casting to a string (#28574)
• Clear sortedness flags in StringChunked substring kernels (#28573)
• Bad mask handling when reading optional parquet column (#28547)
• Any operation on Unknown(Int) and Unknown(Float) should result in Unknown(Float) (#28545)
• Flip nulls_last after Expr.reverse() (#28572)
• Fix high blocking thread use in sink_parquet with async local path (#28543)
• Serialize LazyFrames backed by bytes (#28568)
• Release GIL in SQLContext.execute() (#28549)
• Propagate nulls_last in function_expr_sortedness (#28544)
• Incorrect slicing when a join requires sorting (#28541)

🛠️ Other improvements

• Fix duckdb delta extension install collision (#28607)

Thank you to all our contributors for making this release possible!
@BitWeaverDev, @Matt711, @Samoilov2004, @borchero, @dancsi, @dsprenkels, @kdn36, @masumi-ryugo, @nameexhaustion and @ritchie46