Percona Toolkit is a collection of battle-tested command-line tools for MySQL and MariaDB that help diagnose performance, verify integrity, and perform online maintenance safely. Utilities such as pt-query-digest analyze slow logs and packet captures to surface hotspots and regressions, while pt-online-schema-change applies ALTERs with minimal blocking by copying and swapping tables. Consistency tools like pt-table-checksum and pt-table-sync detect and reconcile replication drift across replicas or shards. ...