Re: IMMUTABLE function's flag do not work: 7.3.4, plpgsql

From: Gaetano Mendola <mendola(at)bigfoot(dot)com>
To: "pgsql-performance(at)postgresql(dot)org" <pgsql-performance(at)postgresql(dot)org>
Cc: Andriy Tkachuk <ant(at)imt(dot)com(dot)ua>
Subject: Re: IMMUTABLE function's flag do not work: 7.3.4, plpgsql
Date: 2003-10-09 16:41:50
Message-ID: 3F858FCE.3040907@bigfoot.com
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Andriy Tkachuk wrote:
> On Wed, 8 Oct 2003, Tom Lane wrote:
>
>
>>Andriy Tkachuk <ant(at)imt(dot)com(dot)ua> writes:
>>
>>>At second. calc_total() is immutable function:
>>>but it seems that it's not cached in one session:
>>
>>It's not supposed to be.
>
>
> but it's written id doc:
>
> IMMUTABLE indicates that the function always returns the same
> result when given the same argument values; that is, it does not
> do database lookups or otherwise use information not directly
> present in its parameter list. If this option is given, any call
> of the function with all-constant arguments can be immediately
> replaced with the function value.

The doc say "can be" not must and will be.

Regards
Gaetano Mendola

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