Path: utzoo!utgpu!news-server.csri.toronto.edu!bonnie.concordia.ca!uunet!decwrl!ucbvax!mtxinu!rtech!ingres!sweeney
From: sweeney@ingres.com (Tony Sweeney)
Newsgroups: comp.databases
Subject: Re: Relational Database info needed.
Message-ID: <1991Jun27.221144.6010@ingres.Ingres.COM>
Date: 27 Jun 91 22:11:44 GMT
References: <5383.28501503@miavx1.acs.muohio.edu} <1991Jun09.222112.10715@chinet.chi.il.us} <1991Jun13.182129.21197@dbase.a-t.com} <13316@sybase.sybase.com} <655@tslwat.UUCP>
Reply-To: sweeney@Ingres.COM (Tony Sweeney)
Organization: Ask Computer Systems Inc., Ingres Division, Alameda CA 94501
Lines: 50

In article <655@tslwat.UUCP> louk@tslwat.UUCP (Lou Kates) writes:
>In article <13316@sybase.sybase.com} tim@ohday.sybase.com (Tim Wood) writes:
>}In article <1991Jun13.182129.21197@dbase.a-t.com} awd@dbase.a-t.com (Alastair Dallas) writes:
>}}Someone writes}
>}}} Ha-ha, not for a year.
>}}this sort of requirement: One database across many environments.  ...
>}}I think product compatibility across platforms is going to be a
>}}significant factor to everyone eventually--apparently Ashton-Tate
>}First?  Ha-ha again.  Can you say "Oracle?"  (Try "Sybase," or "Ingres," 
>}to name two others?)  All these companies have long since committed to a
>}multi-platform marketing strategy.  
>
>I was  under the  impression that  Sybase runs on MS-DOS LANs but
>not on single PCs while the  recent PC Magazine's database  issue
>indicates that  Ingres' MS-DOS LAN does not  even support locking
		 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>on MS-DOS  LANs.  (I have not  used these products so someone can
>correct me  if I  am  mistaken.)  If you want it to run on single
>PCs, MS-DOS LANs as well as  OS/2, UNIX, VAX/VMS,  etc. then  the
>choices are really quite limited and if your requirements include
>referential integrity then, to my knowledge,  there  is   no such
>portable package.
>
>Lou Kates, Teleride Sage Ltd., louk%tslwat@watmath.waterloo.edu

I'd like make clear what Ingres does and doesn't do, since the above
statement is at best misleading. Ingres has essentially two product
families for MS-DOS; Release 5, which offers a stand-alone database,
and Release 6, which proves a client only front end to a server
machine via Ingres/Net. Release 5 "knows" that it is running on a single
processor, has one thread of control, and therefore doesn't need to use
locks on the data. If you have, however, a netware or novell server,
it would be possible to have several PCs attempt to share a single ingres
installation - this would be doomed to failure due to the absence of
locking. Additionally, the cacheing done by most PC lan servers would
compromise data integrity, as when Ingres writes a page to a file it
assumes it has made its way to disk. It is possible to share a single copy
of Ingres (R5 or R6) executables on a PC lan, but the (R5) data must be stored 
on a local disk. Tech support should be able to tell you how to set this up.
In Release 6, this is not an issue, since the server on the target host,
whether OS/2, Unix or VMS handles all the locking issues. Comms protocols
supported include netbios, SPX/IPX, Decnet (PCSA), and various flavours of
TCP. Other PC lan protocols are in the pipeline. In short then, the
original statement is true for the Ingres Release 5 standalone database,
but irrelevant and thus misleading for Release 6.

Tony.
Disclaimer: none of the above is an official statement by Ask Computer
Systems Inc., Ingres Division, but to the best of my knowledge it's all
true :-)