How many reads versus writes?

Do a profile log for some period of time on your OLTP system, and look
at the sum of reads versus the sum of writes.
I just did this, and as expected, there were far more reads than
writes, and even given that I'm counting logical reads versus physical
writes, the difference between the two counts was astounding. I'd be
curious what others see on their systems. Are your read over writes:
90% reads?
99% reads?
99.9% reads?
99.99% reads?
Or anything else?
Curiously,
JoshThis is a very normal observation on an oltp system. It's a mis-conception
that oltp systems write more than they read. Most transactions perform more
reads than writes because of basic things, such as looking up foreign keys,
indexes etc to perform queries. Most GUI screens that users use to interact
with oltp systems are heavily dependant on reads to populate screens, web
pages etc. Generally speaking, users tend to open various screens before
even keying in "stuff" & screens generally need to read the db to populate
fields etc.. In my observations, very high ratios or reads vs writes in oltp
is very normal indeed.
Regards,
Greg Linwood
SQL Server MVP
"jxstern" <jxstern@.nowhere.com> wrote in message
news:f7aap05bvred65fanfnnb2anq2da58hb78@.
4ax.com...
> Do a profile log for some period of time on your OLTP system, and look
> at the sum of reads versus the sum of writes.
> I just did this, and as expected, there were far more reads than
> writes, and even given that I'm counting logical reads versus physical
> writes, the difference between the two counts was astounding. I'd be
> curious what others see on their systems. Are your read over writes:
> 90% reads?
> 99% reads?
> 99.9% reads?
> 99.99% reads?
> Or anything else?
> Curiously,
> Josh
>