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Fwd: [SQL] aggregate function stddev
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* Fwd: [SQL] aggregate function stddev
@ 2004-09-09 18:38  Josh Berkus <[email protected]>
  0 siblings, 1 reply; 2+ messages in thread

From: Josh Berkus @ 2004-09-09 18:38 UTC (permalink / raw)
  To: pgsql-docs

Folks,

Sending this remark to the list so that I/we don't forget to patch it .....

========================================
Just noticed that the postgres stddev is the stddev_sample formula.
There are two different ways to calculate this value.
Their difference is very small with large samle size.  It would be nice
to distinguish the two different versions.
========================================

-- 
Josh Berkus
Aglio Database Solutions
San Francisco



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* Re: Fwd: [SQL] aggregate function stddev
@ 2004-09-09 22:03  Tom Lane <[email protected]>
  parent: Josh Berkus <[email protected]>
  0 siblings, 0 replies; 2+ messages in thread

From: Tom Lane @ 2004-09-09 22:03 UTC (permalink / raw)
  To: Josh Berkus <[email protected]>; +Cc: pgsql-docs

Josh Berkus <[email protected]> writes:
> Sending this remark to the list so that I/we don't forget to patch it .....

> ========================================
> Just noticed that the postgres stddev is the stddev_sample formula.

The documentation already points out that stddev is the sample standard
deviation.

			regards, tom lane




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2004-09-09 18:38 Fwd: [SQL] aggregate function stddev Josh Berkus <[email protected]>
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