Debug Local DB

Debug Local Database

Debug database issues in local or ephemeral environments. Uses Podman (not Docker) for container operations.

Inputs

Workflow

1. Bootstrap

• persona_load("developer") — database and Podman tools
• check_known_issues("psql"), check_known_issues("podman"), check_known_issues("database")

2. Podman Container Checks

• podman_logs(container="postgres") — database logs
• podman_exec(container="postgres", command="psql --version") — PostgreSQL version

3. PostgreSQL Checks

• psql_connections() — active connections
• psql_activity() — current activity
• psql_locks() — lock contention
• psql_size() — database size
• psql_tables() — list tables
• psql_schemas() — list schemas
• psql_query("SELECT pid, now() - pg_stat_activity.query_start AS duration, query, state FROM pg_stat_activity WHERE (now() - pg_stat_activity.query_start) > interval '5 seconds' ORDER BY duration DESC LIMIT 10;") — long-running queries
• psql_describe(table="pg_stat_user_tables") — key tables
• If dump_schema: pg_dump() — full schema dump

4. SQLite (if database == "workflow")

• sqlite_tables() — tables
• sqlite_schema() — schema
• sqlite_query("SELECT name, type FROM sqlite_master WHERE type='table' ORDER BY name;") — basic stats
• sqlite_vacuum() — vacuum

5. Analysis

• Check lock contention in locks output
• Flag long-running queries (>5s)
• Check container logs for "fatal" or "error"
• Parse connection count; flag if > 50

6. Failure Learning

• "connection refused" → learn_tool_fix("psql_connections", "connection refused", "PostgreSQL not running", "Start with podman start postgres")
• "no such container" → learn_tool_fix("podman_logs", "no such container", "Container does not exist", "Create with podman run -d --name postgres postgres:latest")

7. Memory

• memory_session_log("Debug local database ({database})", "healthy=X, issues=Y")

Key MCP Tools

• persona_load, check_known_issues, learn_tool_fix, memory_session_log
• podman_logs, podman_exec
• psql_connections, psql_activity, psql_locks, psql_size, psql_tables, psql_schemas, psql_describe, psql_query, pg_dump
• sqlite_tables, sqlite_schema, sqlite_query, sqlite_vacuum