PostgreSQL Error 2200H: Sequence Generator Limit Exceeded PostgreSQL error code 2200H occurs when a sequence object reaches its defined MAXVALUE (or MINVALUE for descending sequences) and has no CYCLE option to wrap around. This is most commonly seen on tables using SERIAL (INT4) primary keys, which cap out at approximately 2.1 billion . Once the limit is hit, every subsequent INSERT attempting to use that sequence will fail immediately. Top 3 Causes 1. SERIAL Column Hitting the INT4 Ceiling (~2.1 Billion) SERIAL uses a 4-byte integer under the hood. High-volume systems — logging tables, event trackers, order systems — can exhaust this faster than expected. -- Check how close your sequences are to their limit SELECT sequencename , last_value , max_value , ROUND (( last_value :: NUMERIC / max_value ) * 100 , 2 ) AS used_pct , ( max_value - last_value ) AS remaining FROM pg_sequences WHERE schemaname = 'public' ORDER BY used_pct DESC ; Enter fullscreen mode Exit fullscreen mode 2.…