Jeff Janes <jeff.janes@gmail.com> writes:
> 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.
Maybe he's running low on shared_buffers? We would have to flush WAL
before writing a dirty buffer out, so maybe excessive pressure on
available buffers is part of the issue here.
regards, tom lane