Re: [HACKERS] Slow count(*) again...

Mladen Gogala wrote:
> Actually, it is not unlike a religious dogma, only stating that "hints
> are bad". It even says so in the wiki. The arguments are
> 1) Refusal to implement hints is motivated by distrust toward users,
> citing that some people may mess things up.
> Yes, they can, with and without hints.
> 2) All other databases have them. This is a major feature and if I were
> in the MySQL camp, I would use it as an
> argument. Asking me for some "proof" is missing the point. All other
> databases have hints precisely because
> they are useful. Assertion that only Postgres is so smart that can
> operate without hints doesn't match the
> reality. As a matter of fact, Oracle RDBMS on the same machine will
> regularly beat PgSQL in performance.
> That has been my experience so far. I even posted counting query
> results.
> 3) Hints are "make it or break it" feature. They're absolutely needed in
> the fire extinguishing situations.
>
> I see no arguments to say otherwise and until that ridiculous "we don't
> want hints" dogma is on wiki, this is precisely what it is: a dogma.

Uh, that is kind of funny considering that text is on a 'wiki', meaning
everything there is open to change if the group agrees.

> Dogmas do not change and I am sorry that you don't see it that way.
> However, this discussion
> did convince me that I need to take another look at MySQL and tone down
> my engagement with PostgreSQL community. This is my last post on the
> subject because posts are becoming increasingly personal. This level of
> irritation is also
> characteristic of a religious community chastising a sinner. Let me
> remind you again: all other major databases have that possibility:
> Oracle, MySQL, DB2, SQL Server and Informix. Requiring burden of proof
> about hints is equivalent to saying that all these databases are
> developed by idiots and have a crappy optimizer.

You need to state the case for hints independent of what other databases
do, and indepdendent of fixing the problems where the optimizer doesn't
match reatility.

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

+ It's impossible for everything to be true. +