Re: Disabling WAL for bulk data loads

On Fri, Sep 09, 2005 at 11:02:33AM -0500, Kevin Keith wrote:
> I am coming from an Oracle background - which in the case of bulk data
> loads there were several options I had where I could disable writing to the
> redo log to speed up the bulk data load (i.e. direct load, set the user
> session in no archive logging, set the affected tables to have no logging).
>
> I know the COPY command is one option - however it appears the data would
> need to be in formatted file in order to use it correct? I want to avoid
> writing a new file out for the COPY command and loading that.

Well, COPY will give you the best performance. It's also fairly flexable
when it comes to formatting. It shouldn't be difficult to get Oracle's
export tool to generate data that COPY can load.

> What other options does Postgres 7.4 provide which would allow data loads
> to bypass writing to the WAL? I don't need to have this enabled - because
> in the event of a database crash, I would simply reload the data from the
> source files as recovery.

At this point, your only option to change fsync to off in
postgresql.conf and reload the postmaster (kill -HUP). There are plans
to improve support for non-logged tables, but I don't think any of it is
in 8.1.
--
Jim C. Nasby, Sr. Engineering Consultant jnasby(at)pervasive(dot)com
Pervasive Software http://pervasive.com work: 512-231-6117
vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461