Re: [SQL] New Optimizer Behaviour In 7.0b1

Mark Kirkwood <markir(at)ihug(dot)co(dot)nz> writes:
> It looks like the estimate on the big table ( fact1 ) are right order of
> magnitude, but the small table ( dim0 ) ones are too high (and presumably )
> throwing the rest off

At least part of the problem is that the selectivity code doesn't know
how to deal with date/time datatypes :-(. I was waiting for Thomas to
commit the great date/time reorganization before I wrote that code.
But he's done now, so I've gone in and fixed convert_to_scalar to know
about all the surviving date/time types.

If you like, you can pick up the updated version of
src/backend/utils/adt/selfuncs.c from the CVS server, or grab a
snapshot tarball dated later than this message, and see whether
the selectivity estimates get any better.

regards, tom lane