Re: Automatic function replanning

From: Lukas Smith <smith(at)pooteeweet(dot)org>
To: Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us>
Subject: Re: Automatic function replanning
Date: 2005-12-22 21:14:15
Message-ID: 43AB1727.3030902@pooteeweet.org
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Bruce Momjian wrote:

> It is an issue for all databases. We gave a TODO about it:
>
> * Flush cached query plans when the dependent objects change,
> when the cardinality of parameters changes dramatically, or
> when new ANALYZE statistics are available

Ok, just so I understand this correctly. In the mentioned case the
cardinality does not really change in regards to the table stats, its
just thatI happen to use a value that has a different selectivity and
therefore I may need a different plan. So I do not really see how this
use case is handled with the above todo, nor do I really see how its
handled with what Jim suggested earlier. The fact of the matter is that
for this use case you need to use different query plans for the same
prepared statements.

regards,
Lukas

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