Re: Proposal: Pluggable Optimizer Interface - Mailing list pgsql-hackers

From Julius Stroffek
Subject Re: Proposal: Pluggable Optimizer Interface
Date
Msg-id 46C0CCDC.7070906@sun.com
Whole thread Raw
In response to Re: Proposal: Pluggable Optimizer Interface  (Stefan Kaltenbrunner <stefan@kaltenbrunner.cc>)
Responses Re: Proposal: Pluggable Optimizer Interface
List pgsql-hackers
Stefan,

thanks for pointing this out. I missed this change.

We would like to place the hooks to a different place in the planner and we would like to just replace the non-deterministic algorithm searching for the best order of joins and keep the rest of the planner untouched.

I am not quite sure about the usage from the user point of view of what got implemented. I read just the code of the patch. Are there more explanations somewhere else?

I understood that if the user creates his own implementation of the planner which can be stored in some external library, he have to provide some C language function as a "hook activator" which will assign the desired value to the planner_hook variable. Both, the activator function and the new planner implementation have to be located in the same dynamic library which will be loaded when CREATE FUNCTION statement would be used on "hook activator" function.

Am I correct? Have I missed something?

If the above is the case than it is exactly what we wanted except we would like to have the hook also in the different place.

There are more things in the proposal as a new pg_optimizer catalog and different way of configuring the hooks. However, this thinks are not mandatory for the functionality but are more user friendly.

Thanks

Julo

Stefan Kaltenbrunner wrote:
Julius Stroffek wrote: 
Hi All,

Tomas Kovarik and I have presented at PGCon 2007 in Ottawa
the ideas about other possible optimizer algorithms to be used
in PostgreSQL.

We are quite new to PostgreSQL project so it took us some
time to go through the sources end explore the possibilities
how things could be implemented.

There is a proposal attached to this mail about the interface
we would like to implement for switching between different
optimizers. Please review it and provide a feedback to us.
Thank You.   
hmm - how does is that proposal different from what got implemented with:

http://archives.postgresql.org/pgsql-committers/2007-05/msg00315.php


Stefan 

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