|From:||Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>|
|To:||"Tsunakawa, Takayuki" <tsunakawa(dot)takay(at)jp(dot)fujitsu(dot)com>|
|Subject:||Re: Speed up transaction completion faster after many relations are accessed in a transaction|
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"Tsunakawa, Takayuki" <tsunakawa(dot)takay(at)jp(dot)fujitsu(dot)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
regards, tom lane
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