Re: Add min and max execute statement time in pg_stat_statement

On Wed, Oct 23, 2013 at 9:20 AM, Stephen Frost <sfrost(at)snowman(dot)net> wrote:

> Josh,
>
> * Josh Berkus (josh(at)agliodbs(dot)com) wrote:
> > On the other hand, it's still true that a high STDDEV indicates a high
> > variance in the response times of a particular query, whereas a low one
> > indicates that most are close to the average. While precision math
> > might not work if we don't have the correct distribution, for gross DBA
> > checks it's still useful. That is, I can answer the question in many
> > cases of: "Does this query have a high average because of outliers, or
> > because it's consisently slow?" by looking at the STDDEV.
>
> The concern is actually the reverse issue- often the question is "is
> this query ever really slow?", or "when is this query really slow?" and
> those questions are not answered by stddev, min, max, nor avg.
>

How does max not answer "is this query ever really slow?"? But good point,
if we have a max, then I think a time-stamp for when that max was obtained
would also be very useful.

Cheers,

Jeff