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From: tim@ohday.sybase.com (Tim Wood)
Newsgroups: comp.databases
Subject: Re: Why is Oracle better than Ingres
Message-ID: <12054@sybase.sybase.com>
Date: 10 Dec 90 20:29:42 GMT
References: <734@keele.keele.ac.uk> <5550@avocado20.UUCP> <1990Dec2.080257.21343@odi.com> <1338@vision.UUCP> <76172@iuvax.cs.indiana.edu>
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In article <76172@iuvax.cs.indiana.edu> mdchaney@bronze.ucs.indiana.edu (M Darrin Chaney) writes:
>In article <1338@vision.UUCP> chris@vision.UUCP (Chris Davies) writes:
>>In article <5550@avocado20.UUCP> palat@motcid.UUCP (Mohan Palat) writes:
>>> Oracle uses an unusual process architecture (in UNIX). Several 
>>> processes have to be started up before one can even access a 
>>> database. Ingres does not require any such initialization. 
>>
>>In version 6.x of both Ingres and Oracle (and Informix/Turbo too) you need 3
>>or 4 processes running as daemons before you can access any database.  This
>>situation is not just true for Oracle....
>Ingres 6.x has 6 processes that run detached, at least under VMS.  These are
>necessary to do database access, as well as handle internode communication,
>synchronization, etc.  Also, it usually creates a subprocess when someone
>runs Ingres.
>
>This really isn't some big, bad thing, IMHO.
>

It may become a bad thing under load.  Dedicated processes can become
bottlenecks.  It's also instructive to count up how much memory the
service processes occupy, and divide that among all concurrent users
(plus each individual user's DBMS process) to get the per-user memory
usage.  The more memory a user's representation to the DBMS requires,
the less memory will be available for caching database objects.  Also,
it is more likely that paging will occur.  We've found that with large
amounts of memory per user, performance tends to suffer under
moderate-to-large user load.   Of course, one can always scale up the
machine running the DBMS, but all other things being equal, less memory
per user will yield better price/performance.
-TW
Sybase, Inc. / 6475 Christie Ave. / Emeryville, CA / 94608	  415-596-3500
tim@sybase.com          {pacbell,pyramid,sun,{uunet,ucbvax}!mtxinu}!sybase!tim
Dis claim er dat claim, what's da difference?  I'm da one doin da tawkin' hea.