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Re: Review: listagg aggregate

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: "David E. Wheeler" <david@kineticode.com>
Cc: Pavel Stehule <pavel.stehule@gmail.com>, Robert Haas <robertmhaas@gmail.com>, Peter Eisentraut <peter_e@gmx.net>, Scott Bailey <artacus@comcast.net>, "pgsql-hackers@postgresql.org Hackers" <pgsql-hackers@postgresql.org>
Date: 2010-01-26T17:36:13Z
Lists: pgsql-hackers 
"David E. Wheeler" <david@kineticode.com> writes:
> Because it's an aggregate that cocatenates values. It's not an  
> aggregate that lists things. I also like concat_agg better than  
> string_agg because it's not limited to acting on strings.

But what it *produces* is a string.  For comparison, the
SQL-standard-specified array_agg produces arrays, but what it
acts on isn't an array.

			regards, tom lane