[NOVICE] Is now() atomic?

From: Michael Lush <mjlush(at)ebi.ac.uk>
Date: Thu Dec 13 2007 - 11:32:57 EST

I'm writing a reporting script (on postgres 8.1) that logs some table stats along with the time, I'd like to write something like this:-

SELECT now(), foo, COUNT(*) FROM table GROUP BY foo;

               now | foo | count

--------------------------------+-------+-------
  13/12/2007 16:04:49.044687 GMT |  A    | 21499

  13/12/2007 16:04:49.044687 GMT | B | 2517   13/12/2007 16:04:49.044687 GMT | C | 245
.
.

  13/12/2007 16:04:49.044687 GMT | ZZZ | 23016 Does now() record the time that the SELECT statement was executed or the time that the row is printed out?

ie is it possible for the clock to tick during the SELECT resulting in:-

               now | foo | count

--------------------------------+-------+-------

  13/12/2007 16:04:49.044687 GMT | A | 21499
.
.

  13/12/2007 16:04:49.044688 GMT | ZZZ | 23016

--
Michael

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Michael John Lush PhD			Tel:44-1223 492626
Bioinformatician 
HUGO Gene Nomenclature Committee	Email: hgnc@genenames.org
European Bioinformatics Institute
Hinxton, Cambridge
URL: 
http://www.genenames.org
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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Received on Thu Dec 13 11:34:24 2007