Re: [HACKERS] Extended statistics is not working on Vars hidden under a RelabelType

On 13 October 2017 at 02:17, Alvaro Herrera <alvherre@alvh.no-ip.org> wrote:
> I propose this slightly larger change.

hmm, this is not right. You're not checking that there's a Var below
the RelabelType.

I tried with:

explain select * from ab where (a||a)::varchar = '' and b = '';

and your code assumed the OpExpr was a Var.

The reason Tomas coded it the way it was coded is due to the fact that
there's already code that works exactly the same way in
clauselist_selectivity(). Personally, I don't particularly like that
code, but I'd rather not invent a new way to do the same thing.


-- David Rowley                   http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training & Services


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