Re: Huge memory consumption on partitioned table with FKs

On Mon, Mar 8, 2021 at 8:42 PM Amit Langote <amitlangote09(at)gmail(dot)com> wrote:

> Hi Andy,
>
> On Mon, Mar 8, 2021 at 8:39 PM Andy Fan <zhihui(dot)fan1213(at)gmail(dot)com> wrote:
> > On Mon, Mar 8, 2021 at 3:43 PM Andy Fan <zhihui(dot)fan1213(at)gmail(dot)com>
> wrote:
> >> My point below is a bit off-topic, but I want to share it here. Since
> >> we implement a partitioned table in PG with the inherited class, it has
> much
> >> more flexibility than other databases. Like in PG, we allow different
> partitions
> >> have different physical order, different indexes, maybe different
> index states.
> >> that would cause our development work hard in many places and cause some
> >> runtime issues as well (like catalog memory usage), have we discussed
> >> limiting some flexibility so that we can have better coding/running
> experience?
> >> I want to do some research in this direction, but it would be better
> that I can
> >> listen to any advice from others. More specifically, I want to reduce
> the memory
> >> usage of Partitioned table/index as the first step. In my testing,
> each IndexOptInfo
> >> will use 2kB memory in each backend.
> >
> >
> > As for the compatible issue, will it be ok to introduce a new concept
> like "
> > CREATE TABLE p (a int) partitioned by list(a) RESTRICTED". We can add
> these
> > limitation to restricted partitioned relation only.
>
> I think you'd agree that the topics you want to discuss deserve a
> separate discussion thread. You may refer to this discussion in that
> new thread if you think that your proposals can solve the problem
> being discussed here more generally, which would of course be great.
>
>
Sure, I can prepare more data and start a new thread for this.

--
Best Regards
Andy Fan (https://www.aliyun.com/)