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Home -> Community -> Usenet -> c.d.o.server -> Re: Myth of the database independent applications (Was: Are you using PL/SQL)
On Fri, 25 May 2007 10:33:38 -0700, zigzagdna wrote:
> Performance is very complex subject with so many variables, In many of
> our projets there were a few people assigned to do performance
> measueremts on frequenetly used transactions by users and batch
> processes.
Most present day DBA personnel is engaged in performance analysis, much
more seriously then in the good, old days of BCHR and in helping
developers. Being a DBA (Cary Milllsap's term is "performance analyst")
my tuning philosophy always starts with the underlying application. There
is very little that can be done to tune a bad query or to write a good
query in a badly designed schema.
As for the measurements, the only relevant performance measurement is the
response time. If the user community signs off on the application
performance, then the performance is good and should not be investigated
without somebody complaining. If the user community doesn't sign off on
it, the application should be tuned until the response time is
satisfactory. Anjo Kolk, Cary Millsap and Kirti Deshpande are people
who usually get most credit for formulating the wait event/response time
tuning manifesto.
There are many serious performance tuning techniques which involve the
use of sophisticated tuning tools like Mercury LoadRunner and simulation
of a realistic load, yet very few application vendors do that.
Unfortunately, deals are usually not done this way. Software sales people
are the only people that I trust less then used cars sales people or
politicians. When a vendor wants to sell me a piece of "database
independent software" I get extra cautious and ALWAYS ask for references
in a similar configuration as the one they're trying to push. In my
career, I eliminated many companies which were unable to provide such a
reference. People using databases are not a monolithic market, people
using SQL Server and MySQL are generally willing to pay much less then the
people using Oracle or DB2. So called "database independence" is often
just a pretense to grab the money and run. It is my job to ask questions
like "do you feel lucky".
-- http://www.mladen-gogala.comReceived on Fri May 25 2007 - 16:18:45 CDT