Re: Postmaster won't -HUP

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Jerry Lynde <jlynde@diligence.com>
Cc: pgsql-general@postgresql.org
Date: 2000-06-01T21:58:33Z
Lists: pgsql-general
Jerry Lynde <jlynde@diligence.com> writes:
>>>> They are all indexed, the DOB index is actually  DOBYear DOBDay and
>>>> DOBMonth and all 5 fields are indexed
>> 
>> Do you have 5 indexes or do you have an index that spans more than one
>> field?

> Sorry for being less than explicit. There are 5 separate indices, one per 
> field.

So your query is really something more like

	... WHERE firstname = 'joe' AND lastname = 'blow' AND
		  DOByear = 1999 AND DOBmonth = 1 AND DOBday = 1

?

The problem here is that only one index can be used in any individual
scan.  If I were the optimizer I'd probably figure that lastname is
going to be the most selective of the five available choices, too.

I'd suggest storing the DOB as *one* field of type 'date'.  You can
pull out the subparts for display with date_part() when you need to,
but for searches you'll be a lot better off with

		WHERE DOB = '1999-01-01'

			regards, tom lane