Or oracle has it

A DBA can even sit there as queries fly past, and add hints on the fly.

And then you change a query from "select" (lowercase) to "SELECT" (uppercase), and query plans break and you break production.

Fun times

Could you elaborate why changing select from lowercase to uppercase would break anything?

Stored procedures where master and slave are on different OSs and/or case-sensitivity settings are not the same?

Just a guess.