On 17/09/2020 15:06, Tom Lane wrote:
> =?UTF-8?Q?=C3=98ystein_Kolsrud?= <kolsrud@gmail.com> writes:
>> So my question is: When does a postgres process forked for a connection use
>> private memory instead of shared, and what can I do to avoid this?
> The only significant long-term consumption of private memory is for
> caches. There are catalog caches, which can get large if the session
> accesses a whole lot of database objects (e.g., thousands of different
> tables). Some of the PLs maintain caches with parsed versions of any
> function that's been executed. (An ex-employer of mine had a lot of
> trouble in that regard, because they had hundreds of thousands of lines
> worth of plpgsql functions.) There isn't any user-accessible knob for
> limiting the size of those caches. If you have a problem of that sort,
> about the only way to mitigate it is to use fewer backends so that the
> total memory consumption stays in bounds, or redesign your application.
> In some cases it might help to restart your sessions when they get too
> big, but that seems like at best a band-aid.
>
> regards, tom lane
>
>
Would executing DISCARD ALL release the PL cache?
Regards, Chris Sterritt