prole/demo/ci-migration/05_monitor.sql

-- 05_monitor.sql
-- Run this in a SEPARATE psql session while the migration is executing.
-- Poll every few seconds to watch MVCC bloat build up in real time.
--
-- Usage (run continuously):
--   watch -n 3 'PGPASSWORD=... psql -h 127.0.0.1 -p 15432 -U postgres knoe-db -f demo/ci-migration/05_monitor.sql'
--
-- Or in interactive psql with \watch:
--   \i demo/ci-migration/05_monitor.sql
--   \watch 3

\echo '═══════════════════════════════════════════════════════════'
\echo '  MVCC BLOAT MONITOR — updated every \watch cycle'
\echo '═══════════════════════════════════════════════════════════'

\echo ''
\echo '── Long-running transactions (xmin holders) ─────────────'
SELECT pid,
       tx_duration,
       state,
       wait_event_type || '/' || COALESCE(wait_event,'') AS wait,
       left(query_snippet, 80) AS query
FROM demo.long_running_tx
LIMIT 5;

\echo ''
\echo '── xmin horizon (blocks autovacuum cleanup) ─────────────'
SELECT pid, xmin_age, tx_age, state, left(query_snippet, 60) AS query
FROM demo.xmin_horizon
LIMIT 5;

\echo ''
\echo '── Dead tuple accumulation ──────────────────────────────'
SELECT table_name, live_rows, dead_rows, dead_pct, total_size
FROM demo.mvcc_bloat_monitor
LIMIT 10;

\echo ''
\echo '── Active lock waits ────────────────────────────────────'
SELECT blocked_pid, blocking_pid, wait_duration,
       left(blocked_query, 60) AS blocked_q,
       left(blocking_query, 60) AS blocking_q
FROM demo.lock_waits
LIMIT 5;

\echo ''
\echo '── WAL generation progress ──────────────────────────────'
SELECT current_lsn, total_wal, wal_segment_count, wal_dir_size
FROM demo.wal_progress;

\echo ''
\echo '── Autovacuum activity ──────────────────────────────────'
SELECT pid, running_for, left(vacuum_query, 80) AS query
FROM demo.autovacuum_status;