The server terminates a statement because it exceeded the max_execution_time limit.
MySQL error 3024 ER_QUERY_TIMEOUT means the server stopped a query that ran longer than the max_execution_time limit. Optimize the query or raise the limit with SET SESSION max_execution_time to resolve the timeout.
ER_QUERY_TIMEOUT
MySQL raises error 3024 ER_QUERY_TIMEOUT when a running statement surpasses the max_execution_time threshold. The server immediately stops the process and returns the error instead of finishing the result set.
This safeguard prevents runaway or poorly optimized queries from monopolizing CPU, memory, and I/O resources. It first appeared in MySQL 5.7.4 and is available in all later versions, including MySQL 8.0.
The most common trigger is a complex or poorly indexed query that takes longer than the configured limit. If max_execution_time is set to 1000 ms, any statement that hits 1 second is terminated.
Timeouts can also occur when the server is overloaded, storage is slow, or competing transactions hold locks that delay execution beyond the limit.
Start by reading EXPLAIN output to identify full table scans, missing indexes, or costly joins. Adding indexes, simplifying expressions, and avoiding wildcards can reduce runtime below the limit.
When optimization is not enough, raise the limit with SET SESSION max_execution_time = 5000 or disable it by setting the variable to 0.
Select statements on large tables lacking indexes often hit the timeout. Adding composite indexes on filtering columns usually resolves the error.
Analytical GROUP BY or ORDER BY queries may need increased tmp_table_size and work_mem as well as a higher max_execution_time.
Benchmark new queries in a staging environment and review their execution plans before deploying to production.
Use Galaxy s AI copilot to refactor slow statements and surface missing indexes directly inside the editor, then commit trusted queries to a Collection so teammates reuse the optimized version.
Error 3023 (ER_QUERY_TIMEOUT_KILLED) indicates the same timeout but is reported in the error log rather than to the client.
Error 1205 (ER_LOCK_WAIT_TIMEOUT) occurs when a session waits on a lock longer than innodb_lock_wait_timeout; adjusting lock settings, not max_execution_time, resolves that issue.
Multiple joins, subqueries, or functions cause the engine to scan large data sets and exceed the time limit.
Without proper indexes, MySQL performs full table scans that take longer than the configured threshold.
CPU saturation, slow disk I/O, or competing queries extend execution time until the timeout is reached.
Overly aggressive limits terminate queries that would otherwise finish quickly with a higher threshold.
The same timeout detected by an internal kill thread, logged but not returned to the client.
Query waits on row locks too long; solved by adjusting lock timeout or improving transaction design.
Network drop or server crash while executing; check server logs and network stability.
Yes. Set global max_execution_time = 0 in my.cnf or with SET GLOBAL to remove the limit, but monitor for runaway queries.
The limit applies to each SQL statement inside the procedure, not to the procedure as a whole.
Larger buffer pools reduce disk reads, often lowering execution time below the threshold and preventing the error.
Galaxy highlights slow queries, suggests indexes via AI copilot, and lets teams endorse optimized statements so everyone reuses the faster version.
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