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

From Tom Lane
Subject Re: Re: patch: fix performance problems with repated decomprimation of varlena values in plpgsql
Date
Msg-id 1223.1295379745@sss.pgh.pa.us
Whole thread Raw
In response to Re: patch: fix performance problems with repated decomprimation of varlena values in plpgsql  (Noah Misch <noah@leadboat.com>)
Responses Re: Re: patch: fix performance problems with repated decomprimation of varlena values in plpgsql  (Pavel Stehule <pavel.stehule@gmail.com>)
List pgsql-hackers
Noah Misch <noah@leadboat.com> writes:
> On Sun, Jan 16, 2011 at 06:49:27PM +0100, Pavel Stehule wrote:
>> I am sending a updated version with little bit more comments. But I am
>> sure, so somebody with good English have to edit my comments.
>> Minimally I hope, so your questions will be answered.

> Thanks.  I edited the comments and white space somewhat, as attached.  I'll go
> ahead and mark it Ready for Committer.

I looked at this patch and found it fairly awkward.  What is the point
of adding an additional flag to every variable, as opposed to just
forcibly detoasting during assignment?  If it's to avoid detoasting when
the variable is read in a way that doesn't require detoasting, it fails
rather completely IMO, since exec_eval_datum certainly doesn't know
that.

The added memory context variable seems redundant as well.
        regards, tom lane


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