Samuel Gendler writes:
> Answered my own question. Cranking work_mem up to 350MB revealed that
> the in-memory sort requires more memory than the disk sort.
Yeah. The on-disk representation of sortable data is tighter than the
in-memory representation for various reasons, mostly that we're will
On Thu, Aug 19, 2010 at 1:06 AM, Samuel Gendler
wrote:
> Incidentally, if I set values on the connection before querying, is there an
> easy way to get things back to default values or will my code need to know
> the prior value and explicitly set it back? Something like
reset work_mem;
--
Sen
On Thu, Aug 19, 2010 at 12:06 AM, Samuel Gendler
wrote:
> Incidentally, if I set values on the connection before querying, is there
> an easy way to get things back to default values or will my code need to
> know the prior value and explicitly set it back? Something like
>
>
> set work_mem = '5
Incidentally, if I set values on the connection before querying, is there an
easy way to get things back to default values or will my code need to know
the prior value and explicitly set it back? Something like
set work_mem = '512MB'
query
set value = 'default'
or maybe
BEGIN;
set work_mem='
Exactly, it's about the concurrency. I have a server with 128G ram
but it runs dozens of queries at a time for hundreds of clients a
second. The chance that something big for work_mem might jump up and
bite me are pretty good there. Even so, at 16Meg it's not really big
for that machine, and I m
Yeah, although with 48GB of available memory and not that much concurrency,
I'm not sure it matters that much. But point taken, I'll see about modifying
the app such that work_mem gets set on a per-query basis.
On Wed, Aug 18, 2010 at 11:24 PM, Scott Marlowe wrote:
> On Wed, Aug 18, 2010 at 11:4
On Wed, Aug 18, 2010 at 11:45 PM, Samuel Gendler
wrote:
> Answered my own question. Cranking work_mem up to 350MB revealed that
> the in-memory sort requires more memory than the disk sort.
Note that unless you run VERY few client connections, it's usually
better to leave work_mem somewhere in t
Hello
>>
>> I'm not understanding why it is sorting on disk if it would fit within
>> a work_mem segment - by a fairly wide margin. Is there something else
>> I can do to get that sort to happen in memory?
>>
Planner working with estimations. So there is some probability so
planner expected a lar
Answered my own question. Cranking work_mem up to 350MB revealed that
the in-memory sort requires more memory than the disk sort.
On Wed, Aug 18, 2010 at 10:23 PM, Samuel Gendler
wrote:
> I've got this explain: http://explain.depesz.com/s/Xh9
>
> And these settings:
> default_statistics_target =
