 
| Name | Description | Type | Package | Framework | 
| Handler | Called at various points in the JDBC lifecycle. | Interface | org.apache.calcite.avatica | Calcite | 
| Handler .ResultSink | Handler for temporary tables. | Interface | org.apache.calcite.avatica.Handler | Calcite | 
| HandlerImpl | It is recommended implementations of Handler use this as a base class, to ensure forward compatibility. | Class | org.apache.calcite.avatica | Calcite |