I want to be able to customize count SQL or custom Numbers before reading the data

[Tinker666]

Select count(0) from (: SQL) t1 occurs before the start of the read.Under mysql innodb, SQL execution can be very slow.If I could predict the number of rows before reading, I would not be able to execute the SQL.So I wanted to add configuration for custom data volumes.

[sanosay]

I think this is related to this #305 and unfortunately looking at the dates of both issues, I don't see that is going to happen any time soon