Hannu Krosing wrote: > Bruce Momjian kirjutas E, 17.11.2003 kell 03:58: > > > > > OK, let me give you my logic and you can tell me where I am wrong. > > > > First, how many backend can a single write process support if all the > > backends are doing insert/update/deletes? 5? 10? Let's assume 10. > > Second, once we change write to write/fsync, how much slower will that > > be? 100x, 1000x? Let's say 10x. > > > > So, by my logic, if we have 100 backends all doing updates, we will need > > 10 * 100 or 1000 writer processes or threads to keep up with that load. > > That seems quite excessive to me from a context switching and process > > overhead perspective. > > > > Where am I wrong? > > Maybe you meant 100/10 instead of 100*10 ;)
I figured 10 backends, but using fsync, they are not 100x slower (10 * 100). However, testing shows fsync is only 3x slower. -- Bruce Momjian | http://candle.pha.pa.us [EMAIL PROTECTED] | (610) 359-1001 + If your life is a hard drive, | 13 Roberts Road + Christ can be your backup. | Newtown Square, Pennsylvania 19073 ---------------------------(end of broadcast)--------------------------- TIP 8: explain analyze is your friend
