Path: utzoo!attcan!uunet!aplcen!samsung!emory!mephisto!mcnc!rti!dg-rtp!roadkill!cohend
From: cohend@roadkill.rtp.dg.com (Dave Cohen)
Newsgroups: comp.databases
Subject: SQL Precompilers - Revisited
Message-ID: <1990Aug8.153529.12164@dg-rtp.dg.com>
Date: 8 Aug 90 15:35:29 GMT
Sender: usenet@dg-rtp.dg.com (Usenet Administration)
Reply-To: cohend@dg-rtp.dg.com
Organization: Data General Corporation, Research Triangle Park, NC
Lines: 40


Just to clarify a few things -

I meant to stick something in to the
effect that "database restructuring results in reoptimization
on-the-fly, such as the next time the statement is stored.
However, 'restructuring' must be defined in terms that
don't result in reoptimization every time, thus reducing
performance to the same level as dynamic execution. Thus,
a new index would cause reoptimization while the insertion/deletion
of 200 rows would not."

Also, the actual database engine optimizes and stores statements.

The responses I've got are: NCR offers an SQL precompiler
(not sure about platform), Data General offers an SQL precompiler
on its proprietary minis, and CA offers one for VAX/VMS and UNIX.


A few more comments - (heck, I'm losing net access, so flame away!) :

Also, dynamic SQL calls definitely must be supported, but can never
compete performance-wise with precompiled SQL. Currently, they can't
compete in portability either, since every vendor's call level
is completely different while an ANSI standard exists for embedded
SQL in C, COBOL, ADA, FORTRAN, and other languages. I'm not
sure how successful the effort to standardize call level interfaces
will be.

It will always be easier to build an embedded application than a 
function call application, since you only have to know SQL syntax, 
as opposed to SQL syntax and function call syntax. But I would
agree that debugging is harder for precompiled applications unless
the debugger recognizes the embedded source and not the generated
calls.

David Cohen                      |    "There's nothin' wrong with goin'    
cohend@dg-rtp.dg.com             |     nowhere, baby, but we should be   
{world}!mcnc!rti!dg-rtp!cohend   |     should be goin' nowhere fast."       
Data General Corporation, RTP, NC|                  - Streets of Fire