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Re: final patch - plpgsql: for-in-array

Pavel Stehule <pavel.stehule@gmail.com>

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From: Pavel Stehule <pavel.stehule@gmail.com>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, Andrew Dunstan <andrew@dunslane.net>, Merlin Moncure <mmoncure@gmail.com>, Jaime Casanova <jaime@2ndquadrant.com>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Date: 2010-11-18T18:03:28Z
Lists: pgsql-hackers 
2010/11/18 Robert Haas <robertmhaas@gmail.com>:
> On Thu, Nov 18, 2010 at 12:36 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> I would *much* rather we get the performance benefit by internal
>> optimization, and forego inventing syntax.
>
> +1.

any optimization will be about 10-20% slower than direct access. See
my tests: on large arrays isn't significant if you use a simple
expression or full query. This is just overhead from building a
"tuplestore" and access to data via cursor. And you cannot to change a
SRF functions to returns just array. I would to see any optimization
on this level, but I think so it's unreal expecting.

Regards

Pavel Stehule

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