| From: | Marc Mamin <M(dot)Mamin(at)intershop(dot)de> |
|---|---|
| To: | Jeff Janes <jeff(dot)janes(at)gmail(dot)com>, David Osborne <david(at)qcode(dot)co(dot)uk> |
| Cc: | "pgsql-performance(at)postgresql(dot)org" <pgsql-performance(at)postgresql(dot)org> |
| Subject: | Re: GroupAggregate and Integer Arrays |
| Date: | 2015-10-24 20:23:18 |
| Message-ID: | B6F6FD62F2624C4C9916AC0175D56D884209D6B8@jenmbs01.ad.intershop.net |
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| Thread: | |
| Lists: | pgsql-performance |
> CREATE OR REPLACE FUNCTION array_add(int[],int[]) RETURNS int[] AS $$
> -- Add two arrays.
> select
> ARRAY (
> SELECT coalesce($1[i],0) + coalesce($2[i],0)
> FROM (
> select generate_series(least(array_lower($1, 1),array_lower($2,
> 1)), greatest(array_upper($1, 1),array_upper($2, 1)), 1) AS i
> ) sub
> GROUP BY i
> ORDER BY i
> );
> $$ LANGUAGE sql STRICT IMMUTABLE;
it seems that both the GROUP and ORDER BY are superfluous and adding some cycles.
regards,
Marc Mamin
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