Path: utzoo!attcan!utgpu!watserv1!watmath!att!pacbell.com!ucsd!ucbvax!FTP.COM!jbvb
From: jbvb@FTP.COM (James B. Van Bokkelen)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: SQL over DDN
Message-ID: <9012201836.AA01441@ftp.com>
Date: 20 Dec 90 18:36:25 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Reply-To: jbvb@ftp.com
Organization: The Internet
Lines: 19


    I've been thinking about how to implement a distributed database with
    sites located in Hawaii, Alaska, Japan, and Korea.  I see where ORACLE
    (and others) support SQL over tcp/ip networks.  Is there any chance that
    this could be done using the DDN to carry the query/response traffic?

There are two main issues: throughput required, and response time. Things
one would need to know in order to evaluate it are:  How many clients will
be talking to one server?  What's the transaction rate you want to provide
to a single client?  How many data exchanges (and thus round-trip-times)
does a single transaction require?  For what fraction of a transaction will
the database need to be locked against other clients?  What are the minimum,
maximum and average round-trip times you expect the net to provide?  The
major pitfall would appear to be long round-trip-times leaving the files
locked for much longer per transaction than you might initially guess, and
this could greatly reduce the overall transaction rate.

James B. VanBokkelen		26 Princess St., Wakefield, MA  01880
FTP Software Inc.		voice: (617) 246-0900  fax: (617) 246-0901