"Guoping Zhang" <guoping.zhang@xxxxxxxxxx> writes: > Our application has a strict speed requirement for DB operation. Our tests > show that it takes about 10secs for the operation when setting fsync off, > but takes about 70 seconds when setting fsync ON (with other WAL related > parametered tuned). I can't believe that a properly tuned application would have an fsync penalty that large. Are you performing that "operation" as several thousand small transactions, or some such? Try grouping the operations into one (or at most a few) transactions. Also, what wal_buffers and wal_sync_method settings are you using, and have you experimented with alternatives? What sort of platform is this on? What PG version? regards, tom lane
