Re: UPDATEDs slowing SELECTs in a fully cached database

On 7/12/11, lars <lhofhansl@yahoo.com> wrote:
>
>
> The fact that a select (maybe a big analytical query we'll run) touching
> many rows will update the WAL and wait
> (apparently) for that IO to complete is making a fully cached database
> far less useful.
> I just artificially created this scenario.

I can't think of any reason that that WAL would have to be flushed
synchronously.

There is already code that makes transactions that only have certain
kinds of "maintenance" WAL to skip the flush. Could this pruning WAL
be added to that group?