Re: [HACKERS] Much Ado About COUNT(*)

A cardinality estimate function might be nice.
SELECT cardinality_estimate(table_name)
If it is off by 25% then no big deal.
It would be useful for the PostgreSQL query planner also, I imagine.

-----Original Message-----
From: pgsql-general-owner@postgresql.org
[mailto:pgsql-general-owner@postgresql.org] On Behalf Of Wes
Sent: Friday, January 14, 2005 2:59 PM
To: Postgres general mailing list
Subject: Re: [GENERAL] [HACKERS] Much Ado About COUNT(*)

On 1/14/05 12:47 PM, "Frank D. Engel, Jr." <fde101@fjrhome.net> wrote:

> It's probably too messy to be worthwhile this
> way, though.  More trouble than it would be worth.

It would be rather useful if there was a way to get a reasonably
accurate
count (better than analyze provides) in a very short period.  When
you've
got a relatively wide table that has hundreds of millions to over a
billion
rows, and you need to report on how many rows in the table, that can
take a
long time.

Wes



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