Review: listagg aggregate
in [PgSql]
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From: Tom Lane on 26 Jan 2010 11:03 Pavel Stehule <pavel.stehule(a)gmail.com> writes: > 2010/1/25 Robert Haas <robertmhaas(a)gmail.com>: >> On Mon, Jan 25, 2010 at 2:27 PM, David E. Wheeler <david(a)kineticode.com> wrote: >>> concat_agg(). >> >> I like that one... > why is concat_agg better than listagg ? It isn't ... it's the wrong part of speech. "concat"enate is a verb, whereas the other functions we would like it to be named parallel to are using nouns there. (Yes, I know "array" can be used as a verb, but I don't think anyone reads it that way in "array_agg"...) regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers(a)postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
From: "Kevin Grittner" on 26 Jan 2010 11:15 Tom Lane <tgl(a)sss.pgh.pa.us> wrote: > Pavel Stehule <pavel.stehule(a)gmail.com> writes: >> why is concat_agg better than listagg ? > > It isn't ... it's the wrong part of speech. "concat"enate is a > verb, Concatenation is a noun. "concat" doesn't get far enough to distinguish. -Kevin -- Sent via pgsql-hackers mailing list (pgsql-hackers(a)postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
From: Tom Lane on 26 Jan 2010 12:36 "David E. Wheeler" <david(a)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 -- Sent via pgsql-hackers mailing list (pgsql-hackers(a)postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
From: "David E. Wheeler" on 26 Jan 2010 13:04 On Jan 26, 2010, at 9:36 AM, Tom Lane 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. Meh. This is all just bike-shedding. I'm fine with string_agg(), though in truth none of the names has really been great. The inclusion of "agg" in the name is unfortunate. I'll have a look at Pavel's new patch now. David -- Sent via pgsql-hackers mailing list (pgsql-hackers(a)postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
From: Tom Lane on 26 Jan 2010 13:09
"David E. Wheeler" <david(a)kineticode.com> writes: > Meh. This is all just bike-shedding. I'm fine with string_agg(), though in truth none of the names has really been great. The inclusion of "agg" in the name is unfortunate. Yeah, I wouldn't be for it either if it weren't for the precedent of array_agg. I was quite surprised that the SQL committee chose that name, because they've avoided using the term "aggregate function" at all, but there it is ... regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers(a)postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers |