Dawid Kuroczko wrote: > The ext3fs allows to selet type of journalling to be used with > filesystem. Journalling pretty much "mirrors" the work of WAL > logging by PostgreSQL... I wonder which type of journalling > is best for PgSQL in terms of performance. > Choices include: > journal > All data is committed into the journal prior to being > written into the main file system. > ordered > This is the default mode. All data is forced directly > out to the main file system prior to its metadata being > committed to the journal. > writeback > Data ordering is not preserved - data may be written into > the main file system after its metadata has been commit- > ted to the journal. This is rumoured to be the highest- > throughput option. It guarantees internal file system > integrity, however it can allow old data to appear in > files after a crash and journal recovery. > > Am I right to assume that "writeback" is both fastest and at the same > time as safe to use as ordered? Maybe any of you did some benchmarks? Yes. I have seen benchmarks that say writeback is fastest but I don't have any numbers handy. -- Bruce Momjian | http://candle.pha.pa.us pgman@xxxxxxxxxxxxxxxx | (610) 359-1001 + If your life is a hard drive, | 13 Roberts Road + Christ can be your backup. | Newtown Square, Pennsylvania 19073
