On Tue, 26 Mar 2019 at 21:23, Tsunakawa, Takayuki
<tsunakawa.takay@jp.fujitsu.com> wrote:
> Thank you David for explaining. Although I may not understand the effect of "speeding up planning with partitions"
patch,this patch takes effect even without it. That is, perform the following in the same session:
>
> 1. SELECT count(*) FROM table; on a table with many partitions. That bloats the LocalLockHash.
> 2. PREPARE a point query, e.g., SELECT * FROM table WHERE pkey = $1;
> 3. EXECUTE the PREPAREd query repeatedly, with each EXECUTE in a separate transaction. Without the patch, each
transaction'sLockReleaseAll() has to scan the bloated large hash table.
Oh. I think I see what you're saying. Really the table in #2 would
have to be some completely different table that's not partitioned. I
think in that case it should make a difference.
--
David Rowley http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services