Re: Re: patch: fix performance problems with repated decomprimation of varlena values in plpgsql

Robert Haas <robertmhaas@gmail.com> writes:
> On Tue, Jan 18, 2011 at 5:22 PM, Pavel Stehule <pavel.stehule@gmail.com> wrote:
>> opinion isn't strong in this topic. One or twenty useless detoasting
>> isn't really significant in almost use cases (problem is thousands
>> detoasting).

> Yeah.  Many-times-repeated detoasting is really bad, and this is not
> the only place in the backend where we have this problem.  :-(

Yeah, there's been some discussion of a more general solution, and I
think I even had a trial patch at one point (which turned out not to
work terribly well, but maybe somebody will have a better idea someday).
In the meantime, the proposal at hand seems like a bit of a stop-gap,
which is why I'd prefer to see something with a very minimal code
footprint.  Detoast at assignment would likely need only a few lines
of code added in a single place.
        regards, tom lane