Path: utzoo!attcan!uunet!ncrlnk!ncrcae!hubcap!gatech!ncar!tank!uwvax!rutgers!cmcl2!lanl!beta!sas
From: sas@beta.lanl.gov (Steven Smith)
Newsgroups: comp.databases
Subject: Want Information/References on Distributed Databases
Message-ID: <22995@beta.lanl.gov>
Date: 16 Dec 88 19:37:14 GMT
Organization: Los Alamos National Laboratory
Lines: 37

I am looking to the commercial database world to help me leverage a large
problem with a few people.

	We are moving our "system" from 3 VAX 11/785's to N Sun4/260 class
machines.  Our requirements for reliability, flexibility and maintainability 
suggest that talking to a commercial database through SQL would help us
enormously.  The big hitch is that we will have approximately 12 machines
and the rest of the design of the system involves a layering and redundancy
of critical resources such that the effective degradation of the system
is on the order of N where N is the number of machines not working.  This
mostly means having every resource redundant.  For data and databse it
also means having accurate up to date information on each node such that
isolation of the node does not cripple it nor does the loss of any other
node affect it's performance.

	What I need to know is just where distributed database technology
is and how much can we expect from it?  My model is that on each node,
there exists some "work" to do and some "resources" to do it with.  If
the resources aren't available for any reason it is neccesary that other
nodes be able to get at that work and if there is no work to be done it
is desireable that "work" from another node be available to the local
"resource".  Simultaneously, the status of the "work" and the "resources"
needs to be known virtually anywhere and nodes that are temporarily isolated
should be able to continue on their "own" "work" and the other systems
should be aware of the "work" there and it's indeterminate status.

	Yet another constraint is that we use standard interfaces and have
equivalent products available from alternate sources with only performance
differences.  We will be running Sun 4's but can't afford to lock to a single
vendor.  We need to maintain at least the possibility of vendor independence!




Thanks in advance for all your input

Steve