> > Keep in mind that we support platforms without O_DSYNC. I am not > > sure whether there are any that don't have O_SYNC either, but I am > > fairly sure that we measured O_SYNC to be slower than fsync()s on > > some platforms.
This measurement is quite understandable, since the current software does 8k writes, and the OS only has a chance to write bigger blocks in the write+fsync case. In the O_SYNC case you need to group bigger blocks yourself. (bigger blocks are essential for max IO) I am still convinced, that writing bigger blocks would allow the fastest solution. But reading the recent posts the solution might only be to change the current "loop foreach dirty 8k WAL buffer write 8k" to one or two large write calls. Andreas ---------------------------(end of broadcast)--------------------------- TIP 3: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
