Re: controlling memory management with regard to a specific query (or groups of connections)

On 11/19/2015 12:29 PM, Bill Moran wrote:
> On Wed, 18 Nov 2015 20:10:00 -0500
> Jonathan Vanasco <postgres(at)2xlp(dot)com> wrote:
>
>> As a temporary fix I need to write some uploaded image files to PostgreSQL until a task server can read/process/delete them.
>>
>> The problem I've run into (via server load tests that model our production environment), is that these read/writes end up pushing the indexes used by other queries out of memory -- causing them to be re-read from disk. These files can be anywhere from 200k to 5MB.

> ... PostgreSQL doesn't have any provisions for preferring one thing or
> another for storing in memory. The easiest thing I can think would be
> to add memory to the machine (or configure Postgres to use more) such
> that those files aren't pushing enough other pages out of memory to
> have a problematic impact.

Perhaps this is just noise - but how is "just a" 5Mb file upload pushing
critical matter out of memory ? Throttle your file uploads ...

Roxanne