Changes in MySQL 8.0.46 (2026-04-21)

Note

These release notes were created with the assistance of MySQL HeatWave GenAI.

• Audit Log Notes

• Compilation Notes

• SQL Function and Operator Notes

• InnoDB Notes

• JSON Notes

• Optimizer Notes

• Packaging Notes

• X Plugin Notes

• Bugs Fixed

Audit Log Notes

• Fixed an issue related to processing certain gzip files. The MySQL Server has been updated to relax the .gz header checks, allowing ordinary gzip files to be processed. Errors were returned similar to the following:

  Invalid audit log file content

  (Bug #38980223)

Compilation Notes

• The included zlib library has been upgraded to version 1.3.2. (Bug #38987448)

SQL Function and Operator Notes

• Fixed an issue relating to the DEFAULT() function. (Bug #39057054)

InnoDB Notes

• Memory usage during FTS index construction for large tables has been optimized. (Bug #39040226)

• Fixed an issue relating to multi-value indexes. (Bug #39040128)

• Fixed an issue in the parallel reader. (Bug #39033858)

• The MySQL truncate undo operation (purge thread) did not remove the undo_{space_number}_trunc.log file when attempting to truncate the undo tablespace. (Bug #38871808)

• dict_sdi_create_idx_in_mem function added columns in a different order than expected, with the compressed_len and uncompressed_len fields swapped. (Bug #38810801)

• Under certain circumstances, running CREATE INDEX with a high value for --innodb_parallel_read_threads could cause the disk space to fill up, leading to disk space exhaustion. (Bug #38370155)

• Fixed an issue related to TRUNCATE TABLE. (Bug #38169053)

• Under certain circumstances, when calculating the maximum possible index record size, an assertion failure could occur. (Bug #85060, Bug #25579578)

JSON Notes

• Fixed an issue relating to processing of JSON files. (Bug #39000847)

Optimizer Notes

• Fixed an issue relating to optimized prepared DELETE and UPDATE statements. (Bug #39071552)

• Fixed an issue relating to query management. (Bug #38928287)

• Fixed an issue relating to memory management. (Bug #38573278)

• Queries using semi join with materialization may return incorrect results due to a missing condition.

  Our thanks to Jingqi Tian and the team at Alibaba. (Bug #38110792)

• Fixed an issue relating to the Optimizer's SQL planner. (Bug #35634700)

• In an explain expanded query, join order hints were not printed with a valid syntax.

  Our thanks to Kaiwang Chen for the contribution. (Bug #116084, Bug #37053765)

• Conditions on const tables and on previously joined tables were not consistently taken into account when building ranges in get_quick_record_count(). This could lead to suboptimal or incorrect range estimates, especially when range predicates depended on values from const or earlier-joined tables.

  Our thanks to Xingyu Yang for the contribution. (Bug #112737, Bug #35912840)

Packaging Notes

• For platforms on which OpenSSL libraries are bundled, the linked OpenSSL library for MySQL Server has been updated to version 3.5.5. For more information, see OpenSSL 3.5 Series Release Notes. (Bug #38867109, WL #17209)

X Plugin Notes

• The system variable caching_sha2_password_digest_rounds could not be set to a non-default value using X Protocol. (Bug #36402455)

Bugs Fixed

• Fixed an issue relating to Information Schema privileges. (Bug #35243416, Bug #37387633)

• The SQL parser consumed a large amount of memory when parsing very large queries with many large IN clauses.

  As of this release, the SQL parser's memory management has been improved. (Bug #105004, Bug #33390851)