The query returned a string larger than the max_allowed_packet setting, so MySQL aborted with ER_TOO_LONG_STRING (error 1162).
MySQL Error 1162: ER_TOO_LONG_STRING means the result set tried to send a string that exceeds the max_allowed_packet size configured on the server. Increase max_allowed_packet or refactor the query to return a smaller payload to fix the issue.
Result string is longer than 'max_allowed_packet' bytes
Error 1162 fires when a query’s result string exceeds the max_allowed_packet limit, so the server protects itself by aborting the operation.
The error commonly surfaces with GROUP_CONCAT, CONCAT, JSON functions, and large BLOB or TEXT columns. Fixing it is critical because the client never receives the expected data, breaking application workflows.
Oversized GROUP_CONCAT or CONCAT results frequently cross the packet threshold, especially when separator strings are not limited.
Low max_allowed_packet settings on shared or memory-constrained servers trigger the error even with moderate result sizes.
Export tools, ORMs, or Galaxy SQL editor sessions returning large JSON documents can also exceed the limit.
First, check the current packet size using SHOW VARIABLES LIKE 'max_allowed_packet'. If it is below your workload needs, raise it in my.cnf and restart or set it dynamically.
Refactor queries to slice large strings, paginate results, or narrow SELECT columns. When using GROUP_CONCAT, lower group_concat_max_len or use LIMIT within a subquery.
Reporting dashboards that concatenate thousands of IDs often fail; increase max_allowed_packet to 64M and apply LIMIT 1000.
ETL jobs exporting big JSON arrays should stream rows and build JSON client-side instead of single-row JSON_ARRAYAGG.
Always set max_allowed_packet to a value bigger than your largest expected payload plus safety margin.
Monitor packet size metrics and log warnings in Galaxy before executing heavy queries.
Error 1153 appears for incoming packets that are too large. It is fixed with the same max_allowed_packet change.
Error 1406 occurs when data is too long for a column; solve it by widening column types or truncating data.
64M covers most workloads. Very large files may require 256M, but higher values increase memory usage per connection.
A dynamic SET GLOBAL updates running servers, but you must also update my.cnf to survive restarts.
Memory footprint grows, but impact is minimal if typical packets stay small. Monitor connection memory to be safe.
Galaxy warns when a query’s projected output nears the packet limit and suggests pagination or packet tuning before execution.
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