Thread: directly construct a query plan

Hello everyone,
I plan to directly construct a query plan without going through the query
optimizer, by manipulating the various data structures for representing
query plan tree and parse tree. Is there any facility inside/outside
postgresql that can be of help? Is there any known issue/difficulty related
to this?

Thanks!

Steve

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"Chengkai Li" <dbresearch@hotmail.com> writes:
> I plan to directly construct a query plan without going through the query
> optimizer, by manipulating the various data structures for representing
> query plan tree and parse tree. Is there any facility inside/outside
> postgresql that can be of help? Is there any known issue/difficulty related
> to this?

Only that your code *will* break in each future release, because we have
no hesitation about whacking those data structures around ...

            regards, tom lane

Hi Tom,
Thanks!

So if I want to try out some new join algorithm, or even new type of plan
nodes, before I feel the algorithms/nodes are so good that I want to enable
the optimizer to consider them as options, is there any better way to
experiment with possible new plans?

regards,
Steve

> > I plan to directly construct a query plan without going through the
>query
> > optimizer, by manipulating the various data structures for representing
> > query plan tree and parse tree. Is there any facility inside/outside
> > postgresql that can be of help? Is there any known issue/difficulty
>related
> > to this?
>
>Only that your code *will* break in each future release, because we have
>no hesitation about whacking those data structures around ...
>
>            regards, tom lane

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