Re: Tunning postgresql on linux (fedora core 3)

Please CC the mailing list as well as replying to me, so that others can
help too.

Din Adrian wrote:
> yes I have read this as well ...
>
> One question about this option:
> fsync = true / false
> a) I have Raid and UPS - it is safe to turn this off ... (' But be
> very aware that any unexpected database shutdown will force you to
> restore the database from your last backup.' - from my last backup if
> the server goes down ??? why ? just at 'any unexpected database
> shutdown' ? ....!!!!!!!!!!!)

Because fsync=true flushes transaction details to disk (the Write Ahead
Log). That way if (say) the power-supply in your server fails you can
check the WAL and compare it to the main database files to make sure
everything is in a known state.

> b) in docs say that after 7.2 seting this to false does'n turn off the
> wall ...!? wich option does?

The docs don't say that, as far as I can see. It doesn't make sense to
turn off the WAL.
--
Richard Huxton
Archonet Ltd