[PERFORM] Reiser4
ReiserFS 4 is (will be) a filesystem that implements transactions. Are there any plans in a future Postgresql version to support a special fsync method for Reiser4 which will use the filesystem's transaction engine, instead of an old kludge like fsync(), with a possibility of vastly enhanced performance ? Is there also a possibility to tell Postgres : I don't care if I lose 30 seconds of transactions on this table if the power goes out, I just want to be sure it's still ACID et al. compliant but you can fsync less often and thus be faster (with a possibility of setting that on a per-table basis) ? Thanks. ---(end of broadcast)--- TIP 2: you can get off all lists at once with the unregister command (send unregister YourEmailAddressHere to [EMAIL PROTECTED])
Re: [PERFORM] Reiser4
Pierre, Are there any plans in a future Postgresql version to support a special fsync method for Reiser4 which will use the filesystem's transaction engine, instead of an old kludge like fsync(), with a possibility of vastly enhanced performance ? I don't know of any such in progress right now. Why don't you start it? It would have to be an add-in since we support 28 operating systems and Reiser is AFAIK Linux-only, but it sounds like an interesting experiment. Is there also a possibility to tell Postgres : I don't care if I lose 30 seconds of transactions on this table if the power goes out, I just want to be sure it's still ACID et al. compliant but you can fsync less often and thus be faster (with a possibility of setting that on a per-table basis) ? Not per-table, no, but otherwise take a look at the Background Writer feature of 8.0. -- -Josh Berkus A developer of Very Little Brain Aglio Database Solutions San Francisco ---(end of broadcast)--- TIP 7: don't forget to increase your free space map settings
Re: [PERFORM] Reiser4
Pierre-Frédéric Caillaud wrote: Is there also a possibility to tell Postgres : I don't care if I lose 30 seconds of transactions on this table if the power goes out, I just want to be sure it's still ACID et al. compliant but you can fsync less often and thus be faster (with a possibility of setting that on a per-table basis) ? I have been thinking about this. Informix calls it buffered logging and it would be a good feature. Added to TODO: * Allow buffered WAL writes and fsync Instead of guaranteeing recovery of all committed transactions, this would provide improved performance by delaying WAL writes and fsync so an abrupt operating system restart might lose a few seconds of committed transactions but still be consistent. We could perhaps remove the 'fsync' parameter (which results in an an inconsistent database) in favor of this capability. -- 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 5: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faqs/FAQ.html
Re: [PERFORM] Reiser4
Josh Berkus wrote: Pierre, Are there any plans in a future Postgresql version to support a special fsync method for Reiser4 which will use the filesystem's transaction engine, instead of an old kludge like fsync(), with a possibility of vastly enhanced performance ? I don't know of any such in progress right now. Why don't you start it? It would have to be an add-in since we support 28 operating systems and Reiser is AFAIK Linux-only, but it sounds like an interesting experiment. Is there also a possibility to tell Postgres : I don't care if I lose 30 seconds of transactions on this table if the power goes out, I just want to be sure it's still ACID et al. compliant but you can fsync less often and thus be faster (with a possibility of setting that on a per-table basis) ? Not per-table, no, but otherwise take a look at the Background Writer feature of 8.0. Actually the fsync of WAL is the big performance issue here. I added a TODO item about it. -- 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 7: don't forget to increase your free space map settings
