PostgreSQL version 10 WAL 設定概述 參數： checkpoint_timeout default is 5 minute max_wal_size default is 1GB archive_timeout full_page_writes checkpoint_warning checkpoint_completion_target default is 0.5 and only be fraction of checkpoint_timeout pg_test_fsync can measure average speed in microsecond of single WAL flush operation. Half of its value is effective for reporting average time setting that it flush single 8KB write operation to commit_delay. pg_test_fsync doesn’t care whether fsync