On Tue, 2008-03-18 at 21:26 +0700, Artem Yazkov wrote: > Restrictions: > 1. Uninterrupted supply of statistics collector necessary for > efficient use of this algorithm.
In my understanding, we do not guarantee this. That leaves the rest of your ideas drifting, I'm sorry to say. Your ideas and analysis did seem good though, so please don't be put off. > 2. Works only for simplest queries like: > select count (*) from regular_table Personally, I don't see the need to make just that single statement go faster. It only runs slowly on large tables and they seldom need exactly accurate counts frequently enough for us to care. Or put it another way, I never saw a real application where this was a significant performance issue, on any RDBMS. I believe this is a marketing issue for us, only. Other RDBMS supporters know count(*) runs slower on PostgreSQL and use that as evidence of poor performance. We do need a general solution to improving the performance of aggregates, though that is already roughly on the TODO in the shape of materialized view support. -- Simon Riggs 2ndQuadrant http://www.2ndQuadrant.com PostgreSQL UK 2008 Conference: http://www.postgresql.org.uk -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
