SqlReturnTypeInference (Apache Calcite API)

All Known Implementing Classes:

CursorReturnTypeInference, ExplicitReturnTypeInference, MatchReturnTypeInference, OrdinalReturnTypeInference, SqlReturnTypeInferenceChain, SqlTypeTransformCascade, TableFunctionReturnTypeInference
```
public interface SqlReturnTypeInference
```
Strategy interface to infer the type of an operator call from the type of the operands.
This interface is an example of the strategy pattern. This makes sense because many operators have similar, straightforward strategies, such as to take the type of the first operand.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`RelDataType`	`inferReturnType(SqlOperatorBinding opBinding)`	Infers the return type of a call to an `SqlOperator`.

- Method Detail
  - inferReturnType
```
RelDataType inferReturnType(SqlOperatorBinding opBinding)
```
    Infers the return type of a call to an SqlOperator.
    
    Parameters:
    
    opBinding - description of operator binding
    
    Returns:
    
    inferred type; may be null