Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!samsung!uakari.primate.wisc.edu!ames!pacbell!att!cbnewsh!wcs
From: wcs@cbnewsh.ATT.COM (Bill Stewart 201-949-0705 ho95c.att.com!wcs)
Newsgroups: comp.databases
Subject: How fast are Queries, Transactions, Updates?
Message-ID: <5545@cbnewsh.ATT.COM>
Date: 7 Nov 89 16:41:39 GMT
Reply-To: wcs@cbnewsh.ATT.COM (Bill Stewart 201-949-0705 api.att.com!wcs)
Distribution: na
Organization: AT&T Bell Labs 46322
Lines: 26

I'm trying to figure out how fast a machine I need for several
applications.  Most of the DBMS vendors quote their speed as
N transactions/second, where transaction is usually Debit/Credit
hacked to make their system look good but not be quite
comparable to some other DBMS vendor :-).   Typical numbers
seem to be around 5-10 TPS for small machines and 100-200 for
maximum-sized multiprocessors like Pyramid and Sequent.

I'm trying to understand what a "transaction" is for this
purpose - I assume 2-phase commit with a few records updated from
a several tables in a large DBMS?  How much data is in a typical
benchmark query?  What if I want to simply add N records to a
table, presumably updating subtotals - I assume this is much
cheaper than doing N separate transactions?

For most of my applications, however, the major workload isn't
transactions, but just queries into a database that doesn't
change very fast, such as lookups to an index.  How fast are those?
I'd expect to be able to do lots more than 10 Queries/Second on
a 386-box, assuming some well-structured query.

			Thanks;  Bill
-- 
# Bill Stewart, AT&T Bell Labs 4M312 Holmdel NJ 201-949-0705 api.att.com!wcs

#		.... rainbow's end down that highway ....