Path: utzoo!attcan!utgpu!watmath!att!ucbvax!pasteur!eden!mao
From: mao@eden (Mike Olson)
Newsgroups: comp.databases
Subject: Re: Parsing Query Languages in the Client or Server
Message-ID: <17466@pasteur.Berkeley.EDU>
Date: 21 Sep 89 20:13:18 GMT
References: <6155@sybase.sybase.com>
Sender: news@pasteur.Berkeley.EDU
Reply-To: mao@postgres.Berkeley.EDU (Mike Olson)
Organization: University of California, Berkeley
Lines: 40

> From: forrest@sybase.com (Jon Forrest)

> I used to work at Britton Lee. Now I work at Sybase. At Britton Lee
> query languages were parsed in the clients and parse trees were sent
> to the server. Here at Sybase we send the query language to the
> server to be parsed.

with the release of britton lee's server/8000 (known to old-timers like
jon as the omega), this won't be true.  or qualify that:  the full omega
release, including new host software, will send sql strings to the
server for parsing.  i'm not sure where the 8000 is in the release cycle
right now.

among the problems with this approach:  users can't write their own query
languages as easily, though this probably doesn't concern anyone outside
the research world.  also, parameterized strings (that is, substituting
arguments into the string you send) is harder, since the host needs to
know enough about syntax to figure out when to send arguments.  you can
substitute "front end" and "back end" for "host" and "server", here, if
that's what floats your boat.

probably the worst thing about the decision, though, is that it sounds
the death knell of idl, sharebase's quel-like query language, and further
propagates sql.  given that i'm now working on the postgres research
project, heir to ingres, you can imagine where my sympathies lie.

jon's points regarding network traffic, sharability, and early error
detection are all good.  also an issue:  when compiling a C program that
contains embedded database queries, the data server must be up in order
to guarantee that there are no syntax errors in the program.

for the record:  britton lee is now called sharebase.  i no longer work
at sharebase, and do not presume to speak for the company or the people
there.  as an observer, i believe that the decision to move parsing to
the server is a mistake.  it doesn't add any new functionality, and it
has required substantial effort to put in place.

					mike olson
					postgres research group
					mao@postgres.Berkeley.EDU