Re: Speedier count(*) - Mailing list pgsql-performance

From Tino Wildenhain
Subject Re: Speedier count(*)
Date
Msg-id 1123745049.27613.1.camel@Andrea.peacock.de
Whole thread Raw
In response to Re: Speedier count(*)  (Mark Cotner <mcotner@yahoo.com>)
Responses Re: Speedier count(*)
List pgsql-performance
Am Donnerstag, den 11.08.2005, 00:40 -0400 schrieb Mark Cotner:
> Here's a trigger I wrote to perform essentially the same purpose.  The nice
> thing about this is it keeps the number up to date for you, but you do incur
> slight overhead.
...
>
> CREATE TRIGGER del_rowcount_tr BEFORE DELETE ON test FOR EACH ROW EXECUTE
>    PROCEDURE del_rowcount();
> CREATE TRIGGER add_rowcount_tr BEFORE INSERT ON test FOR EACH ROW EXECUTE
>    PROCEDURE add_rowcount();
>
> INSERT INTO rowcount (tablename) VALUES ('test');
...

beware of problems with concurrency and even what happens
if transactions roll back. Maybe you can "fix" it a bit
by regulary correcting the count via cronjob or so.


pgsql-performance by date:

Previous
From: "Chun Yit(Chronos)"
Date:
Subject: Re: it is always delete temp table will slow down the postmaster?
Next
From: Gavin Sherry
Date:
Subject: Re: Speedier count(*)