Re: performance of insert/delete/update

Josh Berkus <josh(at)agliodbs(dot)com> writes:
> One last, last question: I was just asked a question on IRC, and I
> can't find docs defining fsynch, fdatasynch, opensynch, and
> opendatasynch beyond section 11.3 which just says that they are all
> synch methods. Are there docs?

Section 11.3 of what?

The only mention of open_datasync that I see in the docs is in the
Admin Guide chapter 3:
http://developer.postgresql.org/docs/postgres/runtime-config.html#RUNTIME-CONFIG-WAL

which saith

WAL_SYNC_METHOD (string)

Method used for forcing WAL updates out to disk. Possible values
are FSYNC (call fsync() at each commit), FDATASYNC (call
fdatasync() at each commit), OPEN_SYNC (write WAL files with open()
option O_SYNC), or OPEN_DATASYNC (write WAL files with open()
option O_DSYNC). Not all of these choices are available on all
platforms. This option can only be set at server start or in the
postgresql.conf file.

This may not help you much to decide which to use :-(, but it does tell
you what they are.

regards, tom lane