Re: TPC-A and -B Benchmarks

In article <21e3gcINN5q_at_emory.mathcs.emory.edu> SNIEUWEN_at_nl.oracle.com writes:
>X-Informix-List-ID: <list.2469>
>
>In-Reply-To: NLUNIX:rmy.emory.edu!ilist_at_sun4nl.nl.oracle.com's message of 07-06-93 21:11
>Oracle (v6 and Oracle7) *DO* support repeatable reads, *WITHOUT* locking
>whatsoever. By default (so without setting any parameters or changing any

In Oracle 6 to ensure Repeatable Read you have to lock the entire table because otherwise for long running queries you might run out of space in the rollback segments.
Does anybody knows if that's still true for Oracle 7 ???

>settings), Oracle implements statement level multi-version read-consistency.
>This advanced technique will always return correct data for a query, making

Correct data, but not necessarily up-to-date as demanded for stock market, banking and scientific/telecommunications applications.

>Multiple versions of rows can be reconstructed very easy, as this information
>is contained in the rollback data.

Does Oracle maintain multiple versions of rows updated more than once?

>One note: I'm pretty sure Oracle will come up with TPC-C results some time. I
>am not aware of any time scale, but I think TPC-A is still the most accepted at
>this time. One of the purposed of benchmarks is that you can compare (allthough
>very carefully) figures. If almost nobody is running TPC-C's (at this moment
>only IBM as far as I know, both on AS/400 and RS/6000 with Informix), what can
>customers do with these figures, as long as there is nothing to compare it
>with. That's why I think a lot of DB vendors are a bit hesitant to immediately
>start doing TPC-C's.

As everybody knows one must be very careful in interpreting benchmark results if you don't use your own benchmark.
TPC-Cs are intended to address this concern with more realistic true world application simulation.
Eg. TPC-As and TPC-Bs are quite suited for use of discrete transactions but TPC-C is not.

Does anybody know of real world applications using discrete transactions?

>** These opinions are just mine and not of Oracle Corporation **

• These opinions are just mine and not of Informix Software GmbH **

Greetings from Germany,

Alexander
alexk_at_informix.com Received on Wed Jul 07 1993 - 16:46:58 CEST