Re: pgsql: Add support for multivariate MCV lists

On 2019-03-27 19:02:01 +0000, Tomas Vondra wrote:
> Add support for multivariate MCV lists
> 
> Introduce a third extended statistic type, supported by the CREATE
> STATISTICS command - MCV lists, a generalization of the statistic
> already built and used for individual columns.
> 
> Compared to the already supported types (n-distinct coefficients and
> functional dependencies), MCV lists are more complex, include column
> values and allow estimation of much wider range of common clauses
> (equality and inequality conditions, IS NULL, IS NOT NULL etc.).
> Similarly to the other types, a new pseudo-type (pg_mcv_list) is used.
> 
> Author: Tomas Vondra
> Reviewed-by: Dean Rasheed, David Rowley, Mark Dilger, Alvaro Herrera
> Discussion: https://postgr.es/m/dfdac334-9cf2-2597-fb27-f0fb3753f435@2ndquadrant.com

Congrats, this was long in the making!

- Andres