[bonesmoses]

Cross-column statistics are one of my favorites. The way Postgres 10 handles it is really a _huge_ advancement that addresses a painful edge case that has been around for ages.

https://blog.2ndquadrant.com/pg-phriday-crazy-correlated-col...

[ComodoHacker]

To be honest, skewed data problem can be addressed with partitioning in many cases.

Cross-column statistics is a great feature nevertheless.

[pgaddict]

Yes, but partitioning also has a number of limitations that may be quite undesirable. Like inability to create UNIQUE constraints or primary keys, for example.

[anarazel]

More importantly it doesn't help at all with cross-column correlations. It can help with skew in between various rows though.