Checkpoint and WAL configuration mismatches cause I/O spikes

Misconfigured checkpoint and WAL settings can cause periodic I/O spikes, latency spikes during checkpoints, and excessive WAL generation. This impacts write performance and recovery time.

Review checkpoint-related metrics: checkpoint_timed vs checkpoint_requested (too many requested checkpoints indicate configuration issues). Tune max_wal_size and checkpoint_timeout to reduce checkpoint frequency. Monitor checkpoint_write_time and checkpoint_sync_time for I/O impact. Adjust checkpoint_completion_target to spread checkpoint I/O over time.