Re: [PERFORM] max partitions behind a view?
От | Tom Lane |
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Тема | Re: [PERFORM] max partitions behind a view? |
Дата | |
Msg-id | 9918.1505742908@sss.pgh.pa.us обсуждение исходный текст |
Ответ на | [PERFORM] max partitions behind a view? (Rick Otten <rottenwindfish@gmail.com>) |
Список | pgsql-performance |
Rick Otten <rottenwindfish@gmail.com> writes: > The challenge is that because of an exponential rate of data growth, I > might have to significantly increase the number of partitions I'm working > with - to several hundred at a minimum and potentially more than 1000... > This leads me to the question how many 'union all' statements can I have in > one view? I don't think there's a hard limit short of INT32_MAX or so, but I'd be worried about whether there are any O(N^2) algorithms that would start to be noticeable at the O(1000) level. > Should I create a hierarchy of views to gradually roll the data > up instead of putting them all in one top-level view? That would likely make things worse not better; the planner would flatten them anyway and would expend extra cycles doing so. You could perhaps stop the flattening with optimization fences (OFFSET 0) but I really doubt you want the side-effects of that. regards, tom lane -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
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