When grilled further on (Wed, 11 Jan 2006 10:33:03 -0500),
Tom Lane <tgl@sss.pgh.pa.us> confessed:
> The planner understands about transitivity of equality, ie given a = b
> and b = c it can infer a = c. It doesn't do any such thing for
> inequalities though, nor does it deduce f(a) = f(b) for arbitrary
> functions f. The addition Michael suggested requires much more
> understanding of the properties of the functions in your query than
> I think would be reasonable to put into the planner.
>
OK. I think reached a point that I need to re-organize how the data is stored,
maybe ridding myself of the schema and switching entirely to views. At that
point, I likely could rid myself of the function (unmunge_time) I'm using, and
work with times and doy fields.
Thanks,
Rob
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