Replication lag bytes postgres
Measure replica lag in bytes plus write/flush/replay lag intervals
SELECT client_addr, state, pg_wal_lsn_diff(pg_current_wal_lsn(), replay_lsn) AS replay_lag_bytes, write_lag, flush_lag, replay_lag FROM pg_stat_replication;
more postgres
all 29 commands →
Biggest databases
SELECT datname, pg_size_pretty(pg_database_size(datname)) AS size FROM pg_database ORDER BY pg_database_size(datname) DESC;
Table and index sizes
SELECT relname, pg_size_pretty(pg_total_relation_size(oid)) AS total, pg_size_pretty(pg_relation_size(oid)) AS table FROM pg_class WHERE relkind='r' ORDER BY pg_total_relation_size(oid) DESC LIMIT 20;
Find unused indexes
SELECT relname, indexrelname, idx_scan, pg_size_pretty(pg_relation_size(indexrelid)) AS size FROM pg_stat_user_indexes WHERE idx_scan=0 ORDER BY pg_relation_size(indexrelid) DESC;
Check autovacuum status
SELECT relname, n_dead_tup, last_autovacuum, last_autoanalyze FROM pg_stat_user_tables ORDER BY n_dead_tup DESC LIMIT 20;
Reindex without locking
REINDEX INDEX CONCURRENTLY <name>; -- note: cannot run inside a transaction block