Robert Haas <robertmhaas(at)gmail(dot)com> writes:
> On Sat, Oct 17, 2009 at 9:41 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> I've been thinking about this since your earlier mail, and I think it
>> would probably be possible to suppress unused columns in a non-flattened
>> subquery. I remain unconvinced that it's worth the trouble though.
>> A real (not handwavy) example would help make the case here.
> Are there any situations where this would enable join removal that
> otherwise wouldn't be possible?
Hmm, yeah maybe, now that we have some join removal logic. Seems a bit
of a stretch to claim that's a common real-world case though.
regards, tom lane
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