What to do and how often.
MONTHLY
Check the database size in cPanel > MySQL Databases Clear expired transients Empty spam and trashed comments Confirm backups are running and are of plausible size
QUARTERLY
Review the largest tables in phpMyAdmin Clean revisions and orphaned metadata Optimise tables after cleaning Check autoloaded data size, on WordPress Test a restore into a separate database
ANNUALLY
Review which databases exist and remove those for applications you no longer run Review slow queries and indexes Review the table structure for anything that has grown unexpectedly
BEFORE ANY SIGNIFICANT CHANGE
Export the database. Thirty seconds, and it is the only undo available.
AUTOMATING WHAT YOU CAN
A maintenance plugin handles cleanup on a schedule, provided a real cron job is configured.
On our servers HTTP wp-cron is blocked, so scheduled cleanup requires a proper cron entry.
THE TWO THAT MATTER MOST
Backups that actually run, and cleaning bloat before it affects performance.