database-mysql

# MySQL Database ## Authentication **IMPORTANT**: Credentials are injected automatically by a proxy layer. Do NOT check for `MYSQL_PASSWORD` in environment variables - it won't be visible to you. Just run the scripts directly; authentication is handled transparently. Configuration environment variables you CAN check (non-secret): - `MYSQL_HOST` - Database host - `MYSQL_PORT` - Database port (default: 3306) - `MYSQL_DATABASE` - Database name --- ## MANDATORY: Schema-First Investigation **Understand the schema before running queries.** ``` LIST TABLES → DESCRIBE TABLE → EXECUTE QUERY → CHECK HEALTH ``` ## Available Scripts All scripts are in `.claude/skills/database-mysql/scripts/` ### list_tables.py - List Tables (START HERE) ```bash python .claude/skills/database-mysql/scripts/list_tables.py [--database DB] ``` ### describe_table.py - Table Schema Details ```bash python .claude/skills/database-mysql/scripts/describe_table.py --table TABLE_NAME [--database DB] ``` ### execute_query.py - Run SQL Queries ```bash python .claude/skills/database-mysql/scripts/execute_query.py --query "SELECT * FROM users LIMIT 10" [--limit 100] ``` ### show_processlist.py - Active Connections ```bash python .claude/skills/database-mysql/scripts/show_processlist.py [--full] ``` ### show_replica_status.py - Replication Health ```bash python .claude/skills/database-mysql/scripts/show_replica_status.py ``` ### show_engine_status.py - InnoDB Engine Status ```bash python .claude/skills/database-mysql/scripts/show_engine_status.py [--engine innodb] ``` ### get_table_locks.py - Lock Contention ```bash python .claude/skills/database-mysql/scripts/get_table_locks.py ``` --- ## Investigation Workflow ### Slow Query Investigation ``` 1. show_processlist.py --full (find active/long queries) 2. show_engine_status.py (check InnoDB lock waits, deadlocks) 3. get_table_locks.py (find lock contention) ``` ### Replication Lag ``` 1. show_replica_status.py (check Seconds_Behind_Master) 2. show_processlist.py (check for blocking queries) ```