Re: Should we warn against using too many partitions?

Hi David,

On 2019/05/23 18:02, David Rowley wrote:
> Over on [1] I raised a concern about the lack of any warning in our
> documents to inform users that they might not want to use thousands of
> partitions. More recently there's [2], also suffering from OOM using
> 100 partitions. Perhaps there's more too this, but the planner using
> a lot of memory planning updates and deletes to partitioned tables
> does seem to be a surprise to many people.
>
> I had hoped we could get something it the documents sooner rather than
> later about this. Probably the v12 patch will need to be adjusted now
> that the memory consumption will be reduced when many partitions are
> pruned, but I still think v12 needs to have some sort of warning in
> there.
>
> https://commitfest.postgresql.org/23/2065/

The latest patch on the thread linked from this CF entry (a modified
version of your patch sent by Justin Pryzby) looks good to me. Why not
post it on this thread and link this one to the CF entry? Or maybe, make
this an open item, because we should update documentation back to v11?

Thanks,
Amit