Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!ucsd!sdd.hp.com!decwrl!nsc!pyramid!infmx!davek
From: davek@infmx.UUCP (David Kosenko)
Newsgroups: comp.databases
Subject: Re: SQL Precompilers
Message-ID: <4907@infmx.UUCP>
Date: 27 Jul 90 16:07:20 GMT
References: <1990Jul26.141643.6361@dg-rtp.dg.com>
Reply-To: davek@infmx.UUCP (David Kosenko)
Organization: Informix, Menlo Park, Ca. U.S.A.
Lines: 31

In article <1990Jul26.141643.6361@dg-rtp.dg.com> cohend@dg-rtp.dg.com writes:
->I would like to find out from experienced users/developers which
->SQL RDBMs offer true preoptimization. I'm referring to precompilers
->that process host languages with embedded SQL statements, 
->optimize the statements based on database statistics and
->indexes, and generate calls that refer to some statement identifier.
->Simply massaging the SQL into calls that pass the actual
->statement text is definitely not good enough. Neither is forcing
->users to actually make calls that store that statement in the database
->(ie, Sybase stored statements). It appears that most of the database
->vendor hype ignores precompilation, but precompiled applications
->run faster and are easier to code than call level SQL.

	Are you sure you want optimization of embedded SQL statements
to occur at compile time?  Consider what would happen if your schema
changed (adding/dropping indexes) or the profile of your database
changed (e.g. a previously small table grew very large).  That implies
having to recompile your application for optimal performance for
the new situation.
	Informix embedded languages will pass the SQL string to the
engine process via standard function calls.  The engine will then
optimize the statement for processing.  Why is this not "good enough"?
Doesn't that provide the most dynamic and optimal possibility for
statement optimization?

Dave
-- 
Disclaimer:  The opinions expressed herein | There's more than one answer
are by no means those of Informix Software | to these questions pointing me
(though they make you wonder about the     | in a crooked line...
 strange people they hire).                |