Re: Add support for (Var op Var) clause in extended MCV statistics

Hi! I think your work is important)

I started reviewing it and want to suggest some changes to better code: 
I think we should consider the case where the expression is not neither 
an OpExpr and VarOpVar expression.

Have you tested this code with any benchmarks?

-- 
Regards,
Alena Rybakina
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company