Re: "select count(*) from contacts" is too slow!

On Tue, 7 Oct 2003, Paul Serby wrote:

> Why does '*select count(id) from "tblContacts"'* do a sequential scan 
> when the field '*id*' is indexed using a btree?
> 
> MySql simply looks at the index which is keeping a handy record of the 
> number of rows.
> 
> Can anybody explain how and why postgres does this query like it does?

It's a FAQ I believe.

MySQL can tell you from it's index because it doesn't care if it gives you the
right number or not.


--
Nigel Andrews