Suvankar Roy <suvankar(dot)roy(at)tcs(dot)com> wrote:
> Actually I am trying to figure out how much execution time any query
> is taking is taking when executed for the first time.
> Because once a query is executed for the first time, the query plan,
> data buffer is cached so subsequently time taken is much lower.
> For this, I want to have the Shared buffer cache flushed to note
> the initial execution time.
> Is my understanding correct here ?
Keep in mind that the OS cache will also normally have a significant
amount of PostgreSQL data cached. For "uncached" timings, you will
need to purge this, too. Of course, for real-life production
benchmarks the most meaningful timings are normally those taken within
your actual production mix, with all the caching and resource
competition which goes along with that.
In response to
pgsql-admin by date
|Next:||From: Tom Lane||Date: 2009-07-16 21:08:34|
|Subject: Re: convert an Insert Into... select from... to use COPY ? |
|Previous:||From: Kevin Kempter||Date: 2009-07-16 20:14:52|
|Subject: convert an Insert Into... select from... to use COPY ?|