Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!uunet!tut.cis.ohio-state.edu!ucbvax!ucdavis!csusac!unify!nico From: nico@unify.uucp (Nico Nierenberg) Newsgroups: comp.databases Subject: Re: Intelligent Databases (was Re: DB Procedures) Message-ID: Date: 5 Dec 89 17:02:22 GMT References: <4198@rtech.rtech.com> <7323@sybase.sybase.com> <4220@rtech.rtech.com> <7337@sybase.sybase.com> Reply-To: nico@unify.UUCP (Nico Nierenberg) Organization: Unify Corporation, Sacramento, CA, USA Lines: 47 In article <7337@sybase.sybase.com> forrest@sybase.com writes: >In article <4220@rtech.rtech.com> davek@rtech.UUCP (Dave Kellogg) writes: >>3. Single Server >> >> Single multithreaded server which has exclusive control over a set of >> databases. >> Example: Sybase >> >> Strength: Reduced per-user overhead >> Weakness: No multiprocessor support > ^^^^^^^^^^^^^^^^^^^^^^^^^ > >Does this mean that if we come out with a multiprocessor server that >we'll be perfect? > I realize that you are being funny, but there is a serious point here. The answer is no. When you come out with a multi-process server it will have the advantage of multi-processor support, but it will have the disadvantages of having to coordinate multiple OS processes in shared memory. Like all software, DBMS design is a set of trade offs and this is one of them. The reduced per-user overhead was most significant on some of the older machines like the original Sun-3. These machines had relatively primitive CPUs. This made re-mapping large processes very expensive. With the 68030 this re-mapping is virtually free. The major advantage of the single process server today is reduced memory utilization. Of course there is the additional advantage of not needing to coordinate the usage of shared data structures between multiple server processes. It is this advantage which will vanish when Sybase introduces a multiple server product. >---- >Anything you read here is my opinion and in no way represents Sybase, Inc. > >Jon Forrest WB6EDM >forrest@sybase.com >{pacbell,sun,{uunet,ucbvax}!mtxinu}!sybase!forrest >415-596-3422 Nicolas Nierenberg Unify Corp.