Re: Hook for Selectivity Estimation in Query Planning

Hi,

> I would like to discuss the introduction of a hook for evaluating the
> selectivity of an expression when searching for an optimal query plan.
> This topic has been brought up in various discussions, for example, in [1].
>
> [...]

As I vaguely recall recent proposals like this ("Pluggable TOASTer" to
name one) this approach was criticised. Hooks per se don't add value
for the end user. They only put the burden of maintaining them on the
community while all the real features are implemented in proprietar
extensions. If you believe something is missing in Postgres,
contribute it to the upstream so that anyone will benefit from it.

Personally I agree with the sentiment, thus -1.

--
Best regards,
Aleksander Alekseev