allan@dhw68k.cts.com (Alan Perry) (12/04/88)
I am interested in any experiences with the Unisys implementation of
the semantic data model, a product called SIM that runs on Unisys
(Burroughs) A Series machines. I am also interested in general opinions
of the semantic data model.
I work for Unisys in the same building where SIM is worked on and
there was a lot of excitement when SIM was introduced (roughly a
year ago). I know very little about databases and was wondering if
we pulled off any great coup or if anyone noticed (or cared).
Thanks.
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alan perry UUCP: {trwrb,hplabs}!felix!dhw68k!allan
Internet: allan@dhw68k.cts.combeal@dory.cis.ohio-state.edu (Alan Beal) (12/06/88)
In article <16358@dhw68k.cts.com> allan@dhw68k.cts.com (Alan Perry) writes: >I am interested in any experiences with the Unisys implementation of >the semantic data model, a product called SIM that runs on Unisys >(Burroughs) A Series machines. I am also interested in general opinions >of the semantic data model. > >I work for Unisys in the same building where SIM is worked on and >there was a lot of excitement when SIM was introduced (roughly a >year ago). I know very little about databases and was wondering if >we pulled off any great coup or if anyone noticed (or cared). Several comments. At the place of my last employment, we were using DMSII(3.6) and management was very interested in the SIM product as they were looking to modernize their large database system(about 12 Gbytes). One of the major deficiencies with SIM was the lack of an SQL interface. Now I know we all have various opinions on the use of SQL, but if you look at the direction that business is heading, an SQL interface is a must in order to keep your company from being locked into one company's database product - at least that is the theory. Also, most of the business community probably knows little if anything about SIM and couldn't care less. That is the impression I got when I attended last summer's Symposium on Relational Database Systems in Chicago. When I asked the so-called database expert about SIM, he knew very little about it and didn't express an interest in learning about it. It seems DB2 rules the business community. Overall, I liked the DMSII product especially for its media recovery capabilities and its use of Algol as a systems language. But no company is going to turn to SIM if it is not compatible with rest of the world, especially Big Blue. That is reality. SIM is implemented on top of DMSII which may turn out to be a bad design if it is dependent on the underlying database software. I don't know much about SIM but if it was designed with a machine independent interface, I think it would gain wider acceptance especially if UNISYS could convince other vendors to implement SIM on their machines. But I doubt if this is going to happen. One problem Unisys is going to have with the DMSII implementation is that it is a centralized database system. As business moves toward a more distributed approach of computing, this is going to leave Unisys at a disadvantage. I can't comment on whether SIM is a good product or not, but since it is implemented on Unisys Large Systems, most of the business community will probably never know it even existed or even care. -=- Alan Beal The Ohio State University Department of Computer and Information Science beal@cis.ohio-state.edu uucp: osu-cis!lyre.cis.ohio-state.edu!beal