DBMS, August 1996
I find Martin Rennhackkamp's selection of DBMS products very strange. (See "Referential Integrity Control," June 1996.) Perhaps things are different in South Africa. However, the InterBase and SQLBase products have minimal market share and are surely of little interest to most DBMS readers. I find Rennhackkamp's single-sentence mention of Informix with the Progress product insulting and think Informix deserves much better treatment. By some accounts, it is now number two in market share and an excellent product. His failure to make any mention of IBM's DB2 products is also a serious oversight. I would expect better from a fine magazine like DBMS.
Terry Rose
trose@netwizards.net
Your message was forwarded to me. As the editor of DBMS, I appreciate your comments, especially if you feel DBMS is not meeting your needs.
Over time, the Server Side column will examine how several popular servers such as Informix, Oracle, and DB2 implement (or, in some cases, how they fail to support) critical features. On the other hand, market share should not be the sole criterion used to determine which products illustrate the points being made in the article. If SQLBase does something that other servers should do but don't, it is worth knowing about. According to Martin, "I know SQLBase doesn't have a huge market, but the more I evaluate it, the more impressed I am - it has some very, very good features. For the performance monitoring column, it has the best facilities I have encountered so far." By the way, many developers are discovering InterBase because it is bundled with Borland's Delphi development tool, so it, too, deserves greater coverage.
Finally, DBMS has not ignored Informix. Our June cover story surveyed the Informix Enterprise Strategy. Our Internet coverage has not neglected Informix. Both the December 1995 feature article, "Database and the Internet," and our May 1996 Internet Systems supplement cover story, "Shifting Gears," covered the evolution of Informix Internet products and strategies.
- Maurice Frank, Editor
DBMS and Internet Systems
I read with interest Martin Rennhackkamp's article on referential integrity in the June 1996 issue of DBMS magazine. I am a database design consultant specializing in Oracle and Sybase.
He lightly hit upon SQLBase and Oracle allowing declarative cascade delete relationships between tables. This is a huge benefit for database design and, in many cases, is often overlooked. I have seen databases not utilizing these foreign-key relationships that had "orphaned" data everywhere; correct utilization provides "pure" data relationships for business purposes. I think this and row-level locking are the two strongest points Oracle has (purely from a database development view).
In Sybase, you must write the cascade delete relationship with a trigger. This would be a monumental task in the production database designed at my current client site, which consists of 200 tables with 80 percent having the cascade delete relationship (for business rule reasons). Having to build and maintain 160 triggers to do this would be a maintenance nightmare, as well as introducing the human error element of writing a "trigger gone haywire," which will happen eventually.
Great article - the more people aware of different types of relationships and their implementation, the better!
Mark DeArmon
Greenbrier & Russel Inc.
0007007633@mcimail.com