Neil Conway 0ebf1cc834 Implement 4 new aggregate functions from SQL2003. Specifically: var_pop(), ...

var_samp(), stddev_pop(), and stddev_samp(). var_samp() and stddev_samp()
are just renamings of the historical Postgres aggregates variance() and
stddev() -- the latter names have been kept for backward compatibility.
This patch includes updates for the documentation and regression tests.
The catversion has been bumped.

NB: SQL2003 requires that DISTINCT not be specified for any of these
aggregates. Per discussion on -patches, I have NOT implemented this
restriction: if the user asks for stddev(DISTINCT x), presumably they
know what they are doing.

2006-03-10 20:15:28 +00:00

115 KiB

Raw Blame History

View Raw