Re: Why does the number of rows are different in actual and estimated.

Claudio Freire wrote:

> Selectivity is decided based on the number of distinct values on
> both sides, and the table's name "entity" makes me think it's a
> table that is reused for several things. That could be a problem,
> since that inflates distinct values, feeding misinformation to
> the planner.
>
> Rather than a generic "entity" table, perhaps it would be best to
> separate them different entities into different tables.

I missed that; good catch. Good advice.

Don't try to build a "database within a database" by having one
table for different types of data, with a code to sort them out.
EAV is a seriously bad approach for every situation where I've seen
someone try to use it. I was about to say it's like trying to drive
a nail with a pipe wrench, then realized it's more like putting a
bunch of hammers in a bag and swinging the bag at the nail.

-Kevin