Re: "select count(*) from contacts" is too slow!
Ang Chin Han <angch@bytecraft.com.my>
From: Ang Chin Han <angch@bytecraft.com.my>
To: Christopher Browne <cbbrowne@acm.org>
Cc: pgsql-general@postgresql.org
Date: 2003-10-09T04:17:22Z
Lists: pgsql-general
Christopher Browne wrote: > A long time ago, in a galaxy far, far away, nolan@celery.tssi.com wrote: > >>>MySQL can tell you from it's index because it doesn't care if it gives you the >>>right number or not. >> >>Under what circumstances would MySQL give the wrong number? > > > It would give the wrong number under _every_ circumstance where there > are uncommitted INSERTs or DELETEs. Give them some credit. I just double checked: Using mysql 4.0.14 + innodb and transactions, select count(*) from foo; does not count uncommited INSERTs. Heck, even using myisam, mysql's count(*)'s still accurate, since all INSERTs, etc are autocommitted. -- Linux homer 2.4.18-14 #1 Wed Sep 4 13:35:50 EDT 2002 i686 i686 i386 GNU/Linux 12:00pm up 287 days, 3:33, 7 users, load average: 6.93, 6.31, 6.16