MySQL Bugs MySQL AB Bugs Database http://bugs.mysql.com/ MySQL Bugs http://bugs.mysql.com/images/mysql_100x52-64.gif http://bugs.mysql.com/ http://bugs.mysql.com/119442 #119442: Optimizer fails to simplify ORDER BY when column is filtered by IS NULL, causing filesort http://bugs.mysql.com/bug.php?id=119442 Submitted by: Kishore Kumar
Category: Server: Optimizer
Status: Documenting
Severity: 5
OS: Any
Version: 8.4.4
]]> Fri, 21 Nov 2025 20:13:10 +0000 Server: Optimizer http://bugs.mysql.com/67351 #67351: Cardinality samples of partitioned tables sometimes widely off http://bugs.mysql.com/bug.php?id=67351 Submitted by: Patrick van Bergen
Category: Server: Partition
Status: In progress
Severity: 2
OS: Linux
Version: 5.5.27-29.0
]]> Wed, 24 Oct 2012 08:02:07 +0000 Server: Partition http://bugs.mysql.com/120574 #120574: Range optimizer exceeds memory limit and chooses bad range plan for large IN lists http://bugs.mysql.com/bug.php?id=120574 Submitted by: Qingping Zhu
Category: Server: Optimizer
Status: Open
Severity: 2
OS: Any
Version: 8.0.41
]]> Fri, 29 May 2026 14:05:16 +0000 Server: Optimizer http://bugs.mysql.com/120575 #120575: Range optimizer chooses bad range plan for large IN lists and execution is very slow and memory usage spikes. http://bugs.mysql.com/bug.php?id=120575 Submitted by: hel le
Category: Server: Optimizer
Status: Open
Severity: 2
OS: Any
Version: 8.0.41+
]]> Sat, 30 May 2026 06:57:19 +0000 Server: Optimizer http://bugs.mysql.com/120829 #120829: Functional index intermittently unusable under concurrent load: possible_keys=NULL, FORCE INDEX silently ignored http://bugs.mysql.com/bug.php?id=120829 Submitted by: Richard Lohwasser
Category: Server: Optimizer
Status: Open
Severity: 5
OS: Any
Version: 8.4.10, but not 9.7
]]> Wed, 01 Jul 2026 22:32:31 +0000 Server: Optimizer http://bugs.mysql.com/44549 #44549: optimizer incorrectly chooses table scan and filesort over index http://bugs.mysql.com/bug.php?id=44549 Submitted by: Matthew Lord
Category: Server: Optimizer
Status: Verified
Severity: 3
OS: Any
Version: 5.0.80, 5.1.34
]]> Wed, 29 Apr 2009 17:47:30 +0000 Server: Optimizer http://bugs.mysql.com/48049 #48049: SELECT MIN(1) reports differently for MERGE tables in 5.0 and 5.1 http://bugs.mysql.com/bug.php?id=48049 Submitted by: Kyle Joiner
Category: Server: Optimizer
Status: Verified
Severity: 3
OS: Any
Version: 5.1.37, 5.5.7
]]> Wed, 14 Oct 2009 16:46:51 +0000 Server: Optimizer http://bugs.mysql.com/120902 #120902: Hash join AccessPath double-applies probe-side condition filtering http://bugs.mysql.com/bug.php?id=120902 Submitted by: Zack Morgan
Category: Server: Optimizer
Status: Verified
Severity: 5
OS: Linux (Ubuntu (22.04.4 LTS))
Version: 9.7.1
]]> Mon, 13 Jul 2026 09:13:33 +0000 Server: Optimizer http://bugs.mysql.com/120772 #120772: UPDATE HISTOGRAM causes optimizer to use stale cardinalities and miss faster join order http://bugs.mysql.com/bug.php?id=120772 Submitted by: Zack Morgan
Category: Server: Optimizer
Status: Verified
Severity: 5
OS: Ubuntu (22.04.4 LTS)
Version: 9.7.1 and 8.0.31
]]> Thu, 25 Jun 2026 10:27:19 +0000 Server: Optimizer http://bugs.mysql.com/120793 #120793: Default heuristic pruning misses join-connected prefix in 3-table query, causing ~40x slower plan http://bugs.mysql.com/bug.php?id=120793 Submitted by: Zack Morgan
Category: Server: Optimizer
Status: Verified
Severity: 5
OS: Ubuntu (22.04.4 LTS)
Version: 9.7.1
]]> Sat, 27 Jun 2026 11:52:22 +0000 Server: Optimizer http://bugs.mysql.com/120870 #120870: Hypergraph misses BETWEEN equality, causing 100x slowdown http://bugs.mysql.com/bug.php?id=120870 Submitted by: Zack Morgan
Category: Server: Optimizer
Status: Verified
Severity: 5
OS: Ubuntu (22.04.4 LTS)
Version: 9.7.1
]]> Mon, 06 Jul 2026 05:20:06 +0000 Server: Optimizer http://bugs.mysql.com/120868 #120868: Optimizer misses ORDER BY LIMIT optimization when ordering key is equivalent through join equality http://bugs.mysql.com/bug.php?id=120868 Submitted by: Zack Morgan
Category: Server: Optimizer
Status: Verified
Severity: 5
OS: Linux (22.04.4 LTS)
Version: 9.7.1
]]> Sun, 05 Jul 2026 08:42:17 +0000 Server: Optimizer http://bugs.mysql.com/120861 #120861: SELECT DISTINCT inner join expands duplicate-insensitive fanout instead of using semijoin/existence semantics http://bugs.mysql.com/bug.php?id=120861 Submitted by: Zack Morgan
Category: Server: Optimizer
Status: Verified
Severity: 5
OS: Ubuntu (22.04.4 LTS)
Version: 9.7.1
]]> Fri, 03 Jul 2026 12:43:22 +0000 Server: Optimizer http://bugs.mysql.com/120850 #120850: Optimizer misses impossible INNER JOIN condition with IS NULL and normal equality http://bugs.mysql.com/bug.php?id=120850 Submitted by: Zack Morgan
Category: Server: Optimizer
Status: Verified
Severity: 5
OS: Linux (Ubuntu (22.04.4 LTS))
Version: 9.7.1
]]> Fri, 03 Jul 2026 03:32:03 +0000 Server: Optimizer http://bugs.mysql.com/120809 #120809: Optimizer misses DISTINCT early-out and chooses 40M-row hash join Cartesian product http://bugs.mysql.com/bug.php?id=120809 Submitted by: Zack Morgan
Category: Server: Optimizer
Status: Verified
Severity: 5
OS: Ubuntu (22.04.4 LTS)
Version: 9.7.1 and 8.0.31
]]> Mon, 29 Jun 2026 07:31:29 +0000 Server: Optimizer http://bugs.mysql.com/120830 #120830: Optimizer chooses 2800x slower join order despite lower-cost JOIN_PREFIX plan http://bugs.mysql.com/bug.php?id=120830 Submitted by: Zack Morgan
Category: Server: Optimizer
Status: Verified
Severity: 5
OS: Ubuntu (22.04.4 LTS)
Version: 9.7.1
]]> Thu, 02 Jul 2026 03:11:55 +0000 Server: Optimizer http://bugs.mysql.com/120773 #120773: Hash join misses DISTINCT ORDER BY LIMIT early termination http://bugs.mysql.com/bug.php?id=120773 Submitted by: Zack Morgan
Category: Server: Optimizer
Status: Verified
Severity: 5
OS: Ubuntu (Ubuntu (22.04.4 LTS))
Version: 9.7.1
]]> Thu, 25 Jun 2026 11:54:31 +0000 Server: Optimizer http://bugs.mysql.com/120142 #120142: Incorrect result with DISTINCTROW and JSON_OBJECTAGG when replacing COALESCE(SUM(NULL),0) with constant http://bugs.mysql.com/bug.php?id=120142 Submitted by: Wang Ojiken
Category: Server: JSON
Status: Verified
Severity: 3
OS: Any
Version: 8.0.45
]]> Wed, 25 Mar 2026 03:09:27 +0000 Server: JSON http://bugs.mysql.com/120036 #120036: Different results for semantically equivalent expressions using CASE and MIN(CASE ...) with GROUP BY on a FLOAT column http://bugs.mysql.com/bug.php?id=120036 Submitted by: Wang Ojiken
Category: Server: Optimizer
Status: Verified
Severity: 3
OS: Any
Version: 8.0.45
]]> Thu, 12 Mar 2026 02:09:29 +0000 Server: Optimizer http://bugs.mysql.com/120031 #120031: Inconsistent INTERSECT Results in Derived Tables: Impact of PRIMARY KEY on JSON_OBJECTAGG and LEAST Operators http://bugs.mysql.com/bug.php?id=120031 Submitted by: b a
Category: Server: Optimizer
Status: Verified
Severity: 3
OS: Any
Version: 8.4.8
]]> Wed, 11 Mar 2026 14:48:13 +0000 Server: Optimizer http://bugs.mysql.com/119447 #119447: Prepare Statement execute much slower than normal select query http://bugs.mysql.com/bug.php?id=119447 Submitted by: Qingping Zhu
Category: Server: Optimizer
Status: Verified
Severity: 5
OS: CentOS
Version: 8.0.41
]]> Sun, 23 Nov 2025 08:34:44 +0000 Server: Optimizer http://bugs.mysql.com/117164 #117164: Range estimation (index dives) overestimates the rows count on large ranges. It almost doubles the actual number of rows http://bugs.mysql.com/bug.php?id=117164 Submitted by: Alexander Baschuk
Category: Server: Optimizer
Status: Verified
Severity: 3
OS: Any
Version: 8.0.36, 8.0.40
]]> Thu, 09 Jan 2025 06:17:45 +0000 Server: Optimizer http://bugs.mysql.com/116937 #116937: estimation of REF is modified by index diving of INDEX MERGE http://bugs.mysql.com/bug.php?id=116937 Submitted by: NANLONG YU
Category: Server: Optimizer
Status: Verified
Severity: 3
OS: Any
Version: 8.0, 8.0.40
]]> Wed, 11 Dec 2024 08:25:08 +0000 Server: Optimizer http://bugs.mysql.com/116710 #116710: explain shows wrong cost value http://bugs.mysql.com/bug.php?id=116710 Submitted by: Woson Wong
Category: Server: Optimizer
Status: Verified
Severity: 3
OS: Any
Version: 8.0
]]> Tue, 19 Nov 2024 12:47:24 +0000 Server: Optimizer http://bugs.mysql.com/116335 #116335: Multi-valued index isn't used with some range scans on composite indexes http://bugs.mysql.com/bug.php?id=116335 Submitted by: Maciej Dobrzanski
Category: Server: Optimizer
Status: Verified
Severity: 5
OS: Any
Version: 8.0.39
]]> Thu, 10 Oct 2024 16:53:47 +0000 Server: Optimizer http://bugs.mysql.com/115815 #115815: Contribute by tencent: EXPLAIN FORMAT=TREE Incorrectly Shows Cost of Statement http://bugs.mysql.com/bug.php?id=115815 Submitted by: jarne yang
Category: Server: Optimizer
Status: Verified
Severity: 2
OS: Any
Version: 8.4.2
]]> Mon, 12 Aug 2024 02:56:14 +0000 Server: Optimizer http://bugs.mysql.com/112902 #112902: Optimizer in MySQL 8 is significantly slower on dependent subqueries than 5.7 http://bugs.mysql.com/bug.php?id=112902 Submitted by: Oli Sennhauser
Category: Server: Optimizer
Status: Verified
Severity: 5
OS: Linux (n.a.)
Version: 8.0.31, 8.0.35
]]> Tue, 31 Oct 2023 14:39:48 +0000 Server: Optimizer http://bugs.mysql.com/111431 #111431: condition_fanout_filter optimizer wrong result? http://bugs.mysql.com/bug.php?id=111431 Submitted by: Pedro Ferreira
Category: Server: Optimizer
Status: Verified
Severity: 3
OS: Ubuntu (22.04)
Version: 8.0.33
]]> Thu, 15 Jun 2023 08:47:57 +0000 Server: Optimizer http://bugs.mysql.com/110848 #110848: missing considering on order by and limit clause in cost calculation http://bugs.mysql.com/bug.php?id=110848 Submitted by: QIANG TONG
Category: Server: Optimizer
Status: Verified
Severity: 5
OS: Any
Version: 8.0.28, 8.0.33
]]> Thu, 27 Apr 2023 15:04:26 +0000 Server: Optimizer http://bugs.mysql.com/110111 #110111: Optimizer chooses worst plan when index condition pushdown opportunity http://bugs.mysql.com/bug.php?id=110111 Submitted by: Przemyslaw Malkowski
Category: Server: Optimizer
Status: Verified
Severity: 5
OS: Any
Version: 8.0.31
]]> Fri, 17 Feb 2023 12:53:41 +0000 Server: Optimizer