Re: Speed up transaction completion faster after many relations are accessed in a transaction

"Tsunakawa, Takayuki" <tsunakawa.takay@jp.fujitsu.com> writes:
> The attached patch speeds up transaction completion when any prior transaction accessed many relations in the same
session.

Hm.  Putting a list header for a purely-local data structure into shared
memory seems quite ugly.  Isn't there a better place to keep that?

Do we really want a dlist here at all?  I'm concerned that bloating
LOCALLOCK will cost us when there are many locks involved.  This patch
increases the size of LOCALLOCK by 25% if I counted right, which does
not seem like a negligible penalty.

My own thought about how to improve this situation was just to destroy
and recreate LockMethodLocalHash at transaction end (or start)
if its size exceeded $some-value.  Leaving it permanently bloated seems
like possibly a bad idea, even if we get rid of all the hash_seq_searches
on it.

            regards, tom lane