SchemaInfer (TiKV Java Client 3.3.4-SNAPSHOT API)

```
public class SchemaInfer
extends Object
```
SchemaInfer extract row's type after query is executed. It is pretty rough version. Optimization is on the way. The problem we have right now is that TiDB promote Sum to Decimal which is not compatible with column's type. The solution we come up with right now is use record column's type ad finalFieldType and build another list recording TiExpr's type as fieldType for row reading. Once we finish row reading, we first check each element in fieldType and finalFieldType share the same type or not. If yes, no need for casting. If no, casting is needed here.

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`static SchemaInfer`	`create(TiDAGRequest dagRequest)`
`static SchemaInfer`	`create(TiDAGRequest dagRequest, boolean readHandle)`
`DataType`	`getType(int index)`
`List<DataType>`	`getTypes()`

public static SchemaInfer create(TiDAGRequest dagRequest)

public static SchemaInfer create(TiDAGRequest dagRequest,
                                 boolean readHandle)

Class SchemaInfer