Re: Review: listagg aggregate - Mailing list pgsql-hackers

From Pavel Stehule
Subject Re: Review: listagg aggregate
Date
Msg-id 162867791001282343o472f6dfck6f5bd9d98b09acfd@mail.gmail.com
Whole thread Raw
In response to Re: Review: listagg aggregate  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: Review: listagg aggregate  (Robert Haas <robertmhaas@gmail.com>)
List pgsql-hackers
2010/1/28 Tom Lane <tgl@sss.pgh.pa.us>:
> Pavel Stehule <pavel.stehule@gmail.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.

Regards
Pavel Stehule



>
>                        regards, tom lane
>


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