Re: Add min and max execute statement time in pg_stat_statement - Mailing list pgsql-hackers

From Peter Geoghegan
Subject Re: Add min and max execute statement time in pg_stat_statement
Date
Msg-id CAM3SWZTeeL+Rch9-UObftmJowu6rd8fO7B=zzqRbwsjxHPVi1A@mail.gmail.com
Whole thread Raw
In response to Re: Add min and max execute statement time in pg_stat_statement  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
On Mon, Oct 21, 2013 at 4:29 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Hm.  It's been a long time since college statistics, but doesn't the
> entire concept of standard deviation depend on the assumption that the
> underlying distribution is more-or-less normal (Gaussian)?

I don't see how. The standard deviation here would be expressed in
units of milliseconds. Now, that could be misleading, in that like a
mean average, it might "mischaracterize" the distribution. But it's
still got to be a big improvement.

I like the idea of a decay, but can't think of a principled scheme offhand.

-- 
Peter Geoghegan



pgsql-hackers by date:

Previous
From: Andrew Dunstan
Date:
Subject: Re: Add min and max execute statement time in pg_stat_statement
Next
From: Ants Aasma
Date:
Subject: Re: Add min and max execute statement time in pg_stat_statement