Re: Postgresql.conf

But there are ways that we could optimize count(*) queries for specific
circumstances right? Obviously this isn't trivial, but I think it would
be nice if we could maintain a number of rows count that could be used
when performing a count(*) on the whole table (no where clause).

I don't know if the overhead of keeping track of that number is worth
the benefits - but I know that querying for the number of rows in a
table is a common need and other RDBMSs do optimize for that special
case.

On Tue, 23 Jan 2007 12:53:43 -0600, "Bruno Wolff III" <bruno(at)wolff(dot)to>
said:
> On Tue, Jan 23, 2007 at 10:12:13 -0500,
> Brandon Aiken <BAiken(at)winemantech(dot)com> wrote:
> > Out of curiosity, has the COUNT(*) with no WHERE clause slowness been
> > fixed in 8.x? Or is it still an issue of "there's no solution that
> > won't harm aggregates with WHERE clauses"?
>
> Probably not in the sense that you mean.
>
> The underlying problem is that in MVCC there is no single global answer
> to the question and the pain of maintaining the mutliple answers
> outweighs
> the cost of doing so in normal usage.
>
> People that need to run count(*) queries a lot may want to make a
> different
> trade off and some ways of maintaining counts are covered in the
> archives.
>
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