LookupableTableSource (Flink : Table : Common 2.1.0 API)

Type Parameters:

T - type of the result

All Superinterfaces:

TableSource<T>
```
@Deprecated
@Internal
public interface LookupableTableSource<T>
extends TableSource<T>
```
Deprecated.
This interface will not be supported in the new source design around DynamicTableSource. Use LookupTableSource instead. See FLIP-95 for more information.

A TableSource which supports for lookup accessing via key column(s). For example, MySQL TableSource can implement this interface to support lookup accessing. When temporal join this MySQL table, the runtime behavior could be in a lookup fashion.

Method Summary

All Methods Instance Methods Abstract Methods Deprecated Methods
Modifier and Type	Method	Description
`AsyncTableFunction<T>`	`getAsyncLookupFunction(String[] lookupKeys)`	Deprecated. Gets the `AsyncTableFunction` which supports async lookup one key at a time.
`TableFunction<T>`	`getLookupFunction(String[] lookupKeys)`	Deprecated. Gets the `TableFunction` which supports lookup one key at a time.
`boolean`	`isAsyncEnabled()`	Deprecated. Returns true if async lookup is enabled.

Methods inherited from interface org.apache.flink.table.legacy.sources.TableSource
explainSource, getProducedDataType, getReturnType, getTableSchema

- Method Detail
  - getLookupFunction
```
TableFunction<T> getLookupFunction(String[] lookupKeys)
```
    Deprecated.
    
    Gets the TableFunction which supports lookup one key at a time.
    
    Parameters:
    
    lookupKeys - the chosen field names as lookup keys, it is in the defined order
  - getAsyncLookupFunction
```
AsyncTableFunction<T> getAsyncLookupFunction(String[] lookupKeys)
```
    Deprecated.
    
    Gets the AsyncTableFunction which supports async lookup one key at a time.
    
    Parameters:
    
    lookupKeys - the chosen field names as lookup keys, it is in the defined order
  - isAsyncEnabled
```
boolean isAsyncEnabled()
```
    Deprecated.
    
    Returns true if async lookup is enabled.
    The lookup function returned by getAsyncLookupFunction(String[]) will be used if returns true. Otherwise, the lookup function returned by getLookupFunction(String[]) will be used.