Re: Selecting a constant question

From: Dave Page <dpage(at)postgresql(dot)org>
To: Heikki Linnakangas <heikki(at)enterprisedb(dot)com>
Cc: Zeugswetter Andreas ADI SD <ZeugswetterA(at)spardat(dot)at>, "Florian G(dot) Pflug" <fgp(at)phlo(dot)org>, Dann Corbit <DCorbit(at)connx(dot)com>, Hannu Krosing <hannu(at)skype(dot)net>, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, Gregory Stark <stark(at)enterprisedb(dot)com>, pgsql-hackers(at)postgresql(dot)org
Subject: Re: Selecting a constant question
Date: 2007-06-12 11:18:39
Message-ID: 466E810F.40107@postgresql.org
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

Heikki Linnakangas wrote:
> Actually, if you're in such a high throughput, client-side CPU-intensive
> situation that this makes any difference, why are you copying the value
> to another buffer in the first place? Just access it directly in the
> libpq buffer returned by PQgetvalue, and move on.

That's a *very* good point. The original design for the pgAdmin query
tool made it's own copy of the data to display in the grid which is
exactly why we used to get complaints about having a query time and a
display time.

The modern versions use a virtual table which enables the grid to
retrieve the data directly from the libpq buffer when it needs to draw
each cell which has effectively eliminated that display time.

Regards, Dave.

In response to

Browse pgsql-hackers by date

  From Date Subject
Next Message Zdenek Kotala 2007-06-12 11:20:21 Re: Autovacuum launcher doesn't notice death of postmaster immediately
Previous Message Heikki Linnakangas 2007-06-12 11:01:10 Re: Selecting a constant question