Re: speeding up planning with partitions

On Fri, 8 Feb 2019 at 14:34, Imai, Yoshikazu
<imai(dot)yoshikazu(at)jp(dot)fujitsu(dot)com> wrote:
>
> On Wed, Feb 6, 2019 at 2:04 AM, Tsunakawa, Takayuki wrote:
> > Can you compare the performance of auto and force_custom_plan again with
> > the attached patch? It uses PGPROC's LOCALLOCK list instead of the hash
> > table.
>
> Thanks for the patch, but it seems to have some problems.
> When I executed create/drop/select commands to large partitions, like over than 512 partitions, backend died unexpectedly. Since I could see the difference of the performance of auto and force_custom_plan when partitions is large, patch needs to be modified to check whether performance is improved or not.

It's good to see work being done to try and improve this, but I think
it's best to do it on another thread. I think there was some agreement
upthread about this not being Amit's patch's problem. Doing it here
will make keeping track of this more complex than it needs to be.
There's also Amit's issue of keeping his patch series up to date. The
CFbot is really useful to alert patch authors when that's required,
but having other patches posted to the same thread can cause the CFbot
to check the wrong patch.

--
David Rowley http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services