Re: Review: listagg aggregate

From: Robert Haas <robertmhaas(at)gmail(dot)com>
To: Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>
Cc: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, Takahiro Itagaki <itagaki(dot)takahiro(at)oss(dot)ntt(dot)co(dot)jp>, "David E(dot) Wheeler" <david(at)kineticode(dot)com>, "pgsql-hackers(at)postgresql(dot)org Hackers" <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: Review: listagg aggregate
Date: 2010-01-29 18:43:04
Message-ID: 603c8f071001291043j6160f82fx573f4f57af81753a@mail.gmail.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

On Fri, Jan 29, 2010 at 2:43 AM, Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com> wrote:
> 2010/1/28 Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>:
>> Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com> writes:
>>> with get_fn_expr_arg_stable() we are able to fix second parameter
>>> without some performance issues.
>>
>> No, that will create its own performance issues ---
>> get_fn_expr_arg_stable isn't especially cheap.
>> If there were a really strong reason why we had to do it,
>> then I'd agree, but frankly the argument for disallowing
>> a variable delimiter is too thin.
>
> it could be called only once. But I agree, so could be better, check
> it in parser time.
>
> ok - I am only one who like original behave - so I  am withdrawing.
> Robert, If you like, please commit Itagaki's patch. + add note about
> behave when second parameter isn't stable.

I haven't even looked at this code - I sort of assumed Itagaki was
handling this one. But it might be good to make sure that the docs
have been read through by a native English speaker prior to commit...

...Robert

In response to

Responses

Browse pgsql-hackers by date

  From Date Subject
Next Message David E. Wheeler 2010-01-29 18:45:09 Re: Review: listagg aggregate
Previous Message Simon Riggs 2010-01-29 18:39:05 pgsql: Augment WAL records for btree delete with GetOldestXmin() to