RE: Speed up transaction completion faster after many relations areaccessed in a transaction
От | Tsunakawa, Takayuki |
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Тема | RE: Speed up transaction completion faster after many relations areaccessed in a transaction |
Дата | |
Msg-id | 0A3221C70F24FB45833433255569204D1FC8416D@G01JPEXMBYT05 обсуждение исходный текст |
Ответ на | Re: Speed up transaction completion faster after many relations areaccessed in a transaction (David Rowley <david.rowley@2ndquadrant.com>) |
Ответы |
Re: Speed up transaction completion faster after many relations areaccessed in a transaction
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Список | pgsql-hackers |
From: David Rowley [mailto:david.rowley@2ndquadrant.com] > Another counter-argument to this is that there's already an > unexplainable slowdown after you run a query which obtains a large > number of locks in a session or use prepared statements and a > partitioned table with the default plan_cache_mode setting. Are we not > just righting a wrong here? Albeit, possibly 1000 queries later. > > I am, of course, open to other ideas which solve the problem that v5 > has, but failing that, I don't see v6 as all that bad. At least all > the logic is contained in one function. I know Tom wanted to steer > clear of heuristics to reinitialise the table, but most of the stuff > that was in the patch back when he complained was trying to track the > average number of locks over the previous N transactions, and his > concerns were voiced before I showed the 7% performance regression > with unconditionally rebuilding the table. I think I understood what you mean. Sorry, I don't have a better idea. This unexplanability is probably what we shouldaccept to avoid the shocking 7% slowdown. OTOH, how about my original patch that is based on the local lock list? I expect that it won't that significant slowdownin the same test case. If it's not satisfactory, then v6 is the best to commit. Regards Takayuki Tsunakawa
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