Update datatypes.md

Author: jovezhong

docs/datatypes.md

@@ -6,9 +6,9 @@ Like many analytics systems, the following common types are supported.
 
 | Category                      | Type       | Example                              | Note                                                         | Related functions                                            |
 | ----------------------------- | ---------- | ------------------------------------ | ------------------------------------------------------------ | ------------------------------------------------------------ |
-| Numeric Types                 | integer    | -100                                 | default with 4 bytes. Same as `int32`. You can also use `int`, `int8`, `int64`, `smallint`, `bigint`, or `uint16` etc. | [to_int](/functions_for_type#to_int)                          |
+| Numeric Types                 | integer    | -100                                 | default with 4 bytes. Same as `int32`. You can also use `int`, `int8`, `int16`, `int32`, `int64`, `smallint`, `bigint`, or `uint16` etc. | [to_int](/functions_for_type#to_int)                          |
 |                               | decimal    | 3.14                                 | decimal(precision, scale). Valid range for precision is [1: 76], valid range for scale is [0: precision] | [to_decimal](/functions_for_type#to_decimal)                  |
-|                               | float      | -3.1415                              | default with 4 bytes. Same as `float32`. You can also use `float64` or `double` for 8 bytes | [to_float](/functions_for_type#to_float)                      |
+|                               | float      | -3.1415                              | default with 4 bytes. Same as `float32`. You can also use `float64` or `double` for 8 bytes. No `float8` or `float16`. | [to_float](/functions_for_type#to_float)                      |
 | Boolean Type                  | bool       | true                                 | true or false                                                |                                                              |
 | String Type                   | string     | 'Hello'                              | strings of an arbitrary length. You can also use `varchar` To create string columns with fixed size in bytes, use `fixed_string(positiveInt)` | [to_string](/functions_for_type#to_string), [etc.](/functions_for_text) |
 | Universally Unique Identifier | uuid       | 1f71acbf-59fc-427d-a634-1679b48029a9 | a universally unique identifier (UUID) is a 16-byte number used to identify records. For detailed information about the UUID, see [Wikipedia](https://en.wikipedia.org/wiki/Universally_unique_identifier) | [uuid](/functions_for_text#uuid)                              |