Related to #1847 Here's list of mathematics funcitons supported by TiKV but not supported by TiFlash: - [x] Ceil - [x] Ceiling - [x] Floor - [x] Sqrt - [ ] Sign - [x] Ln - [x] Log - [x] Log2 - [x] Log10 - [x] Exp - [x] Pow - [x] Radians - [x] Degrees - [x] Conv - [x] CRC32 Besides, we need to support more mathematics functions.