Re: On query rewrite

>>>>> "Tom" == Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> writes:

Tom> This particular issue is handled as part of our Path
Tom> enumeration mechanism, but the more hard-wired sorts of
Tom> transformations that you are asking about live mostly in

Thanks again. To confirm the actual cost comparison with plan
enumeration is a dynamic programming algorithm, is it not ?
Selinger-style with 2-way join paths enumerated, then 3-way using the
best 2-way etc. ?

BTW, do lots of people use the GEQO ?

Tom> optimizer/prep/* and plan/planner.c. In particular you
Tom> probably want to look at prepjointree.c and prepqual.c.
Tom> (Note prepqual also looks considerably different in CVS tip
Tom> than in prior releases.)

Thanks .. I've extracted cvstip .. sigh .. one of these days I'll have
to do another merge with the TelegraphCQ code. You guys hack too much :-)

--
Pip-pip
Sailesh
http://www.cs.berkeley.edu/~sailesh