Re: Performance of a large array access by position (tested version 9.1.3)

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От Cédric Villemain
Тема Re: Performance of a large array access by position (tested version 9.1.3)
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Msg-id 201206281222.45642.cedric@2ndquadrant.com
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Ответ на Re: Performance of a large array access by position (tested version 9.1.3)  (Pavel Stehule <pavel.stehule@gmail.com>)
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> >> >>> Is that behaviour is correct?
> >>
> >> yes - access to n position means in postgresql - skip n-1 elements
> >
> > Hmmm...
> >
> > how many elements to be skipped here ?
>
> there are two independent stages:
>
> a) detoast - loading and decompression (complete array is detoasted)
> b) access
>
> if you has very large arrays, then @a is significant

There is a place to add PG_GETARG_ARRAY_P_SLICE. The code is just not done
yet.

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Cédric Villemain +33 (0)6 20 30 22 52
http://2ndQuadrant.fr/
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