Re: Is a Multithreaded Ingres On the Horizon???
Date: 6 Sep 1993 03:41:21 GMT
Message-ID: <26ebh1INN4n2_at_ariel.ucs.unimelb.EDU.AU>
perl_at_dwrsun4.UUCP (Robert Perlberg) writes:
|There could be other advantages besides prioritizing. I have found
|that a single Ingres server can only seem to handle 2 queries at a
|time. We have had situations where 2 big queries (big being defined as
|queries which take many minutes to run) were running on the same server
|process at the same time. During this time, no other users could start
|any queries on this server and users just trying to connect could not
|connect. At the time we were running one DBMS server on a one-cpu
|machine. Having two big queries running effectively shut down the
|system for all the other users. Running multiple DBMS servers, even on
|a one-cpu machine, solved this problem. The machine may not run at
|100% efficiency under these conditions, but a slightly slower than
|normal system is much better than a completely dead one. So, I regard
|the number of DBMS servers to be more a function of how many concurrent
|users you need to support rather than how many cpu's you have.
You probably could have solved this problem by playing with the -quantum parameter in rundbms.opt. This allows you to change the time sharing between cpu intensive queries to prevent them monoplizing the server. See the dba guide for details.
-- Richard Begg (richard_at_asis.unimelb.edu.au) Admin Systems and Info Services - University of Melbourne.Received on Mon Sep 06 1993 - 05:41:21 CEST