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From: "Fernando Hevia" <fhevia@ip-tel.com.ar>
To: "'Tom Lane'" <tgl@sss.pgh.pa.us>
Cc: "'SQL Postgresql List'" <pgsql-sql@postgresql.org>
Subject: Re: Function Volatility 
Date: Mon, 10 Sep 2007 10:47:34 -0300
Organization: IP-TEL
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Tom Lane writes:

> The IMMUTABLE marker is a promise from you to the system that it is safe
> to optimize away multiple calls to the function.  It is not a promise
> from the system to you that the system will expend unlimited amounts of
> energy to detect duplicate calls.

Nicely put. Thanks!
BTW, this explanation should go into the manual.

Regards,
Fernando.