Re: patch: fix performance problems with repated decomprimation of varlena values in plpgsql - Mailing list pgsql-hackers

On 11/22/2010 07:46 AM, Pavel Stehule wrote:
> Hello
>
> this patch remove a multiple detoasting of varlena values in plpgsql.
>
> It is usable mainly for iteration over longer array directly loaded
> from relation.
>
> It's doesn't have a impact on semantic or behave - it's just eliminate
> some performance trap.
>
> sample: table 10000 rows one column with array with 1000 string fields:
>
> patched pl time: 6 sec
> unpatched pl time: 170 sec
>

Since you haven't told us exactly how you tested this it's hard to gauge 
the test results.

cheers

andrew