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From: miket@blia.BLI.COM (Mike Tossy)
Newsgroups: comp.databases
Subject: Re: Parsing Query Languages in the Client or Server
Message-ID: <9463@blia.BLI.COM>
Date: 25 Sep 89 22:49:20 GMT
References: <6155@sybase.sybase.com> <6167@sybase.sybase.com> <1989Sep24.215650.15732@odi.com>
Organization: Britton Lee, Los Gatos, CA
Lines: 56

> 
>    > At Britton Lee
(ShareBase)
>    > 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.
>
(Note the use of past tense.  This is changing for exactly the reasons outlined
below.)
>
>    ...  The world is moving toward
>    open, standardized interfaces.  There is already an ANSI SQL standard,
>    and a subcommittee of ANSI X3H2 is working on remote database access
>    protocols.  Eventually, a client will be able to run queries on anyone's
>    server without having to know much about the server. 
> 
> 

(For completeness let me offer these comments):

One argument in favor of parsing (or at least scanning) on the client:

Imagine a network with hundreds of clients talking to a few servers.  The
clients represent a very valuable source of MIPS - MIPS which are fairly
difficult to apply to the core of the RDBMS problem, but which are easy
to apply to the scanning/parsing problem.  In this scenerio a server
which used server based scanning/parsing would need to be bigger than a
server that used client based scanning/parsing.


Another argument in favor of client based scanning/parsing:

Precompiler code probably needs to be scanned on the client anyway; so
using a server based scanning/parsing system results in double scanning.


Personnally I think a good case can be made for either side; but the new
standards are going toward scanning/parsing on the server and therefore
it is the existance of a standard, not the merits of the technical argument
that will decide where to do the parsing.  (I am reminded of the time C.J. Date
was a guest at our user's group and one customer asked if SQL or QUEL
was the better langauge (we offer both).  Date responded "QUEL, but it
doesn't matter; SQL is the standard").

Final note: parsing on the client does NOT mean you can use a dumb terminal
connected directly to a server.  You still need "smarts" on the client end.


Mike Tossy                                      ShareBase Coropration
miket@blia.bli.com                              14600 Wichester Blvd
(408) 378-7575 ext2200                          Los Gatos, CA 95030
					(Formerly: Britton Lee, Inc.)
					 
The preceeding might or might not be close to the opinion of ShareBase Corp;
if you think I bothered to clear it with anybody other than myself you're
crazy.