From: Louis-David Mitterrand <vindex+lists-pgsql-sql@apartia.org>
To: pgsql-sql@postgresql.org
Subject: Re: Does IMMUTABLE property propagate?
Date: Thu, 25 Mar 2010 07:16:17 +0100
Message-ID: <20100325061616.GA4629@apartia.fr> (raw)
In-Reply-To: <4150.1267911115@sss.pgh.pa.us>
References: <4B91C184.4090906@venaver.info>
<407d949e1003060645i408e0648te67dfd722172f76a@mail.gmail.com>
<4B927FED.60209@venaver.info>
<4150.1267911115@sss.pgh.pa.us>
On Sat, Mar 06, 2010 at 04:31:55PM -0500, Tom Lane wrote:
> Petru Ghita <petrutz@venaver.info> writes:
> > "..immediately replaced with the function value" doesn't mean that the
> > results of a previously evaluated function for the same parameters are
> > stored and reused?
>
> No, it means what it says: the function is executed once and replaced
> with a constant representing the result value.
So for example a function like:
CREATE OR REPLACE FUNCTION shorten_cruise_type(intext text) RETURNS text
AS $$
declare
outtext text;
begin
outtext = trim(regexp_replace(intext, E'\\s*Short( Break)?', '', 'i'));
return outtext;
end;
$$
LANGUAGE plpgsql;
could/should be declared immutable?
Thanks,
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To: pgsql-sql@postgresql.org
Cc: vindex+lists-pgsql-sql@apartia.org
Subject: Re: Does IMMUTABLE property propagate?
In-Reply-To: <20100325061616.GA4629@apartia.fr>
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