Re: Review: listagg aggregate

Robert Haas <robertmhaas@gmail.com>

From: Robert Haas <robertmhaas@gmail.com>

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

Cc: "David E. Wheeler" <david@kineticode.com>, Pavel Stehule <pavel.stehule@gmail.com>, Peter Eisentraut <peter_e@gmx.net>, Scott Bailey <artacus@comcast.net>, "pgsql-hackers@postgresql.org Hackers" <pgsql-hackers@postgresql.org>

Date: 2010-01-27T22:09:14Z

Lists: pgsql-hackers

On Tue, Jan 26, 2010 at 1:38 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Robert Haas <robertmhaas@gmail.com> writes:
>> On Tue, Jan 26, 2010 at 12:36 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>>> 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.
>
>> This point is well-taken, but naming it string_agg() because it
>> produces a string doesn't seem quite descriptive enough.  We might
>> someday (if we don't already) have a number of aggregates that produce
>> an output that is a string; we can't name them all by the output type.
>
> True, but the same point could be made against array_agg, and that
> didn't stop the committee from choosing that name.  As long as
> string_agg is the "most obvious" aggregate-to-string functionality,
> which ISTM it is, I think it's all right for it to have pride of place
> in naming.

Maybe so, but personally, I'd still prefer something more descriptive.

...Robert