Database Table Optimization

ZiziCache can optimize database tables using MySQL OPTIMIZE TABLE. Optimization is triggered manually from the Database tools or via the REST API; it is not executed automatically as part of the scheduled cleanup job.

Types of Table Optimization

The plugin provides two execution paths with different scopes:

• Standard optimization (admin quick action /optimize-db-tables): optimizes only non-InnoDB tables that show fragmentation (data_free > 0).
• Safe batch optimization (/optimize-db-tables-batch): processes tables one by one and includes InnoDB tables only when fragmentation is detected (data_free > 0).

Safety Measures

Safety controls depend on the execution path:

• Fragmentation check: tables are selected using data_free from information_schema.
• Size limit (batch only): tables larger than 500 MB are skipped.
• Per-table processing (batch only): tables are optimized sequentially with a short pause between runs.
• Transaction wrappers (batch only): non-InnoDB tables are wrapped with START TRANSACTION/COMMIT/ROLLBACK.

Optimization Statistics

Detailed statistics are returned only by the batch endpoint:

• Total optimized, skipped, and error counts
• Saved bytes per table
• Per-table execution time and status
• Skip reasons or error messages

The standard optimization action does not return per-table statistics.

Automatic Optimization

The db_optimize_tables flag enables table optimization when it is explicitly requested (manual cleanup or REST API). The scheduled cleanup job does not run table optimization automatically.