Re: Add min and max execute statement time in pg_stat_statement

Josh,

* Josh Berkus (josh@agliodbs.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.