Re: How to get parallel restore in PG 8.4 to work?

>> I still have some work to do to find out why dumping in the custom
>> format is so much slower.
>
> Offhand the only reason I can see for it to be much different from
> plain-text output is that -Fc compresses by default. If you don't
> care about that, try -Fc -Z0.

Ok, I did some performance testing today and I appeared to be wrong after all. My apologies for the noise.
Here are some test results:
Scenarioxfsjfs patchedjfscat backup | gunzip | psql45 min--pg_dump> hdd (uncompressed) (==pg_dump -Fp)--10 min 15 secpg_dump -Fc> hdd (uncompressed)10 min 20 sec10 min 21 sec10 min 28 secpg_dump -Fc | gzip> hdd11 min 20 sec11 min 25 sec12 min 04 secpg_restore 8 threads14 min 23 sec11 min 40 sec11 min 20 secpg_restore 16 threads11 min 46 sec12 min 40 sec12 min 33 secpg_restore 32 threads11 min 42 sec12 min 30 sec12 min 30 sec
As can be seen in the table (hope this renders correctly on the mailing list), there is barely a difference between a plain dump and a custom format dump. For who it concerns, xfs performance a little better than jfs here, but the difference is marginal. More on topic, beyond 16 processes there isn't any notable speed improvement for the parallel restore (as expected).
Kind regards,Henk
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