Re: Slow performance on MAX(primary_key)
Ludwig Lim <lud_nowhere_man@yahoo.com>
From: Ludwig Lim <lud_nowhere_man@yahoo.com>
To: Keith Gray <keith@heart.com.au>
Cc: PostgreSQL Mailing List <pgsql-sql@postgresql.org>
Date: 2002-10-15T07:16:28Z
Lists: pgsql-sql
Hi Keith: --- Keith Gray <keith@heart.com.au> wrote: > Help, > > I have just been comparing some large table > performance > under 7.1 using the > > select max(primary key)from table; > > We are using this for various functions including > sequence. > Try using the following as alternative : SELECT primary_key FROM table ORDER BY primary_key desc LIMIT 1; This should work if primary_key is indexes. As of now, Max() doesn't utilizes the indices hence it always do a sequential scan. Hope that helps, regards, ludwig. __________________________________________________ Do you Yahoo!? New DSL Internet Access from SBC & Yahoo! http://sbc.yahoo.com