1796
MySQLERRORCommonPartitioningHIGH confidence
Row found in wrong partition
Production Risk
Critical — data integrity compromised; queries may return incorrect results.
What this means
During partition maintenance (REORGANIZE, CHECK, or REPAIR PARTITION), a row was found stored in a partition that does not match the row's partition key value.
Why it happens
- 1Partition definition was changed without migrating existing data.
- 2Data corruption in the partition metadata.
- 3Direct manipulation of InnoDB data files.
How to reproduce
trigger — this will error
trigger — this will error
CHECK TABLE partitioned_tbl; -- discovers rows in wrong partitions
expected output
ERROR 1796 (HY000): Row in wrong partition: {db}.{table} partition {p_old}.Fix
Use ALTER TABLE ... REBUILD PARTITION or OPTIMIZE PARTITION to redistribute rows
Use ALTER TABLE ... REBUILD PARTITION or OPTIMIZE PARTITION to redistribute rows
ALTER TABLE partitioned_tbl REBUILD PARTITION ALL;
Why this works
Rebuilds all partitions, moving rows to the correct partition based on current partition rules.
What not to do
✕
Sources
Official documentation ↗
MySQL 8.0 — 1796 ER_ROW_IN_WRONG_PARTITION
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