***************
May 2024 Update
***************

Documentation
=============

* Publish blog post about `optimizing TRY and TRY_CAST <https://velox-lib.io/blog/optimize-try-more>`_
* Publish `Technical Governance <https://velox-lib.io/docs/community/technical-governance>`_.

Core Library
============

* Optimize TRY and TRY_CAST for cases when many rows fail.
* Add support for LEFT SEMI FILTER and RIGHT SEMI FILTER merge joins.
* Add support for DECIMAL input to aggregations over distinct values. :pr:`9850`
* Add support for specifying overwrite behavior when registering simple scalar functions. :pr:`9158`
* Fix LEFT merge join with extra filter. :pr:`9862`
* Fix Nested Loop join with empty build and extra filter. :pr:`9892`
* Fix crash when copying complex vectors. :pr:`9725`
* Fix reuse of LazyVectors in TableScan to avoid crashes in downstream operators. :pr:`9811`
* Add support for including metadata identifying the operator that generated an error in error messages to ease troubleshooting. :pr:`9695`

Presto Functions
================

* Add :func:`at_timezone` function.
* Add support for VARBINARY input to :func:`approx_distinct` aggregate function.
* Add support for CAST(varchar AS timestamp with time zone).
* Add support for DECIMAL inputs to :func:`min_by` and :func:`max_by` aggregate functions.
* Fix :func:`arrays_overlap` function for empty arrays. :pr:`9922`
* Fix :func:`map_top_n` function to break ties by comparing keys.
* Fix CAST(IntervalDayTime AS Varchar) for negative intervals. :pr:`9871`
* Fix :func:`from_base64` for inputs without padding. :pr:`8647`
* Fix handling of equality and total ordering of NaN (Not-a-Number) floating point
  values in :func:`array_min`, :func:`array_sort`, :func:`array_distinct`,
  :func:`array_except`, :func:`array_intersect`, :func:`array_union`,
  :func:`array_position`, :func:`array_remove`, :func:`arrays_overlap`, :func:`contains`,
  map subscript and :func:`multimap_agg`.

Spark Functions
===============

* Add :spark:func:`expm1`, :spark:func:`get`, :spark:func:`rint`, :spark:func:`shuffle`,
  :spark:func:`soundex`, :func:`unix_seconds`, :spark:func:`width_bucket` functions.
* Add support for complex type inputs to :spark:func:`hash` and :spark:func:`xxhash64` functions.
* Fix CAST(tinyint/smallint/integer/bigint as varbinary). :pr:`9819`
* Fix return type for :spark:func:`sum` aggregate function with REAL input. :pr:`9818`

Hive Connector
==============

* Add support for projecting synthesized row-number column from Table Scan. :pr:`9174`

Performance and Correctness
===========================

* Optimize memory arbitration to avoid interference between queries to reduce overall query execution time.
* Add cache expiration function to simple LRU cache to support remote IO throttling.
* Add Fuzzers for TableWriter and RowNumber operators.
* Add support for Nested Loop joins to Join Fuzzer.
* Add support for testing different sorting flags to Window Fuzzer.
* Add custom argument type generators for Presto decimal functions. :pr:`9715`
* Add support for logical input types in the evaluateOnce() unit test helper method. :pr:`9708`
* Re-enable testing of merge joins in Join Fuzzer.

Build System
============

* Upgrade aws-sdk-cpp to 1.11.321 (from 1.11.169).
* Upgrade cmake to 3.28.3 (from 3.14).
* Upgrade simdjson to 3.9.3 (from 3.8.0).
* Add support for docker image with Spark Connect server to use with Fuzzer. :pr:`9759`
* Add dashboard with `build time metrics <https://facebookincubator.github.io/velox/bm-report/>`_.

Credits
=======

Ankita Victor, Ashwin Krishna Kumar, Bikramjeet Vig, Bradley Dice, Daniel Munoz,
Deepak Majeti, Giuseppe Ottaviano, Jacob Wujciak-Jens, Jia Ke, Jialiang Tan,
Jimmy Lu, Joe Abraham, Karteekmurthys, Ke, Kevin Wilfong, Kk Pulla, Krishna
Pai, Ma,  Rong, Masha Basmanova, NEUpanning, PHILO-HE, Patrick Sullivan, Pedro
Eugenio Rocha Pedreira, Richard Barnes, Sandino Flores, Sergey Pershin, Ubuntu,
Wei He, Weihan Tang, Yang Zhang, Zac Wen, Zuyu ZHANG, aditi-pandit, chliang,
duanmeng, gaoyangxiaozhu, jay.narale, joey.ljy, kevin, kikimo, lingbin, rui-mo,
svm1, xiaoxmeng, xumingming, yan ma, yanngyoung, yingsu00, zhli1142015,
zhouyifan279, zjuwangg, zky.zhoukeyong, 高阳阳