Re: [PATCHES] Avg performance for int8/numeric
От | Tom Lane |
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Тема | Re: [PATCHES] Avg performance for int8/numeric |
Дата | |
Msg-id | 19371.1164561276@sss.pgh.pa.us обсуждение исходный текст |
Ответ на | Re: [PATCHES] Avg performance for int8/numeric ("Simon Riggs" <simon@2ndquadrant.com>) |
Ответы |
Re: [PATCHES] Avg performance for int8/numeric
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Список | pgsql-hackers |
"Simon Riggs" <simon@2ndquadrant.com> writes: > On Sat, 2006-11-25 at 18:57 +1300, Mark Kirkwood wrote: >> Also Neil suggested investigating using a single composite type >> {int8, >> numeric} for the {N,sum(X)} transition values. This could well be a >> faster way to do this (not sure how to make it work yet... but it >> sounds >> promising...). > If that is true it implies that any fixed length array is more expensive > than using a composite type. Not sure how you derived that conclusion from this statement, but it doesn't appear to me to follow at all. The reason for Neil's suggestion was to avoid using numeric arithmetic to run a simple counter, and the reason that this array stuff is expensive is that the array *components* are variable-length, which is something that no amount of array redesigning will eliminate. regards, tom lane
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