3086
MySQLERRORNotablePartitioningHIGH confidence
Failed to read partition .par file
Production Risk
High — the partitioned table may be inaccessible.
What this means
MySQL could not read the .par file for a partitioned table, typically due to a missing, corrupted, or inaccessible file.
Why it happens
- 1The .par file was deleted or moved outside of MySQL.
- 2File system permissions prevent MySQL from reading the datadir.
- 3Corruption after a crash or improper shutdown.
How to reproduce
trigger — this will error
trigger — this will error
-- Triggered when opening or accessing a partitioned table
expected output
ERROR 3086 (HY000): Failed to read from the .par file.
Fix 1
Restore the .par file from backup
Restore the .par file from backup
-- Copy .par file from backup to the MySQL datadir
Why this works
Restores the partition metadata file.
Fix 2
Use ALTER TABLE to rebuild partitions
Use ALTER TABLE to rebuild partitions
ALTER TABLE t REBUILD PARTITION ALL;
Why this works
Recreates partition files from existing data.
What not to do
✕
Sources
Official documentation ↗
MySQL 8.0 — 3086 ER_FAILED_READ_FROM_PAR_FILE2
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