org.apache.flink.table.client.gateway

Interface Executor

All Known Implementing Classes:

LocalExecutor

public interface Executor

A gateway for communicating with Flink and other external systems.

Method Summary

Modifier and Type	Method and Description
void	cancelQuery(SessionContext session, String resultId) Cancels a table program and stops the result retrieval.
List<String>	completeStatement(SessionContext session, String statement, int position) Returns a list of completion hints for the given statement at the given position.
ResultDescriptor	executeQuery(SessionContext session, String query) Submits a Flink SQL query job (detached) and returns the result descriptor.
ProgramTargetDescriptor	executeUpdate(SessionContext session, String statement) Submits a Flink SQL update statement such as INSERT INTO.
String	explainStatement(SessionContext session, String statement) Returns a string-based explanation about AST and execution plan of the given statement.
Map<String,String>	getSessionProperties(SessionContext session) Lists all session properties that are defined by the executor and the session.
TableSchema	getTableSchema(SessionContext session, String name) Returns the schema of a table.
List<String>	listTables(SessionContext session) Lists all tables known to the executor.
List<String>	listUserDefinedFunctions(SessionContext session) Lists all user-defined functions known to the executor.
TypedResult<List<Tuple2<Boolean,Row>>>	retrieveResultChanges(SessionContext session, String resultId) Asks for the next changelog results (non-blocking).
List<Row>	retrieveResultPage(String resultId, int page) Returns the rows that are part of the current page or throws an exception if the snapshot has been expired.
TypedResult<Integer>	snapshotResult(SessionContext session, String resultId, int pageSize) Creates an immutable result snapshot of the running Flink job.
void	start() Starts the executor and ensures that its is ready for commands to be executed.
void	stop(SessionContext session) Stops the executor.
void	validateSession(SessionContext session) Validates the current session.

Method Detail

start

void start()
    throws SqlExecutionException

Starts the executor and ensures that its is ready for commands to be executed.

Throws:

SqlExecutionException

getSessionProperties

Map<String,String> getSessionProperties(SessionContext session)
                                 throws SqlExecutionException

Lists all session properties that are defined by the executor and the session.

Throws:

SqlExecutionException

listTables

List<String> listTables(SessionContext session)
                 throws SqlExecutionException

Lists all tables known to the executor.

Throws:

SqlExecutionException

listUserDefinedFunctions

List<String> listUserDefinedFunctions(SessionContext session)
                               throws SqlExecutionException

Lists all user-defined functions known to the executor.

Throws:

SqlExecutionException

getTableSchema

TableSchema getTableSchema(SessionContext session,
                           String name)
                    throws SqlExecutionException

Returns the schema of a table. Throws an exception if the table could not be found. The schema might contain time attribute types for helping the user during debugging a query.

Throws:

SqlExecutionException

explainStatement

String explainStatement(SessionContext session,
                        String statement)
                 throws SqlExecutionException

Returns a string-based explanation about AST and execution plan of the given statement.

Throws:

SqlExecutionException

completeStatement

List<String> completeStatement(SessionContext session,
                               String statement,
                               int position)

Returns a list of completion hints for the given statement at the given position.

executeQuery

ResultDescriptor executeQuery(SessionContext session,
                              String query)
                       throws SqlExecutionException

Submits a Flink SQL query job (detached) and returns the result descriptor.

Throws:

SqlExecutionException

retrieveResultChanges

TypedResult<List<Tuple2<Boolean,Row>>> retrieveResultChanges(SessionContext session,
                                                             String resultId)
                                                      throws SqlExecutionException

Asks for the next changelog results (non-blocking).

Throws:

SqlExecutionException

snapshotResult

TypedResult<Integer> snapshotResult(SessionContext session,
                                    String resultId,
                                    int pageSize)
                             throws SqlExecutionException

Creates an immutable result snapshot of the running Flink job. Throws an exception if no Flink job can be found. Returns the number of pages.

Throws:

SqlExecutionException

retrieveResultPage

List<Row> retrieveResultPage(String resultId,
                             int page)
                      throws SqlExecutionException

Returns the rows that are part of the current page or throws an exception if the snapshot has been expired.

Throws:

SqlExecutionException

cancelQuery

void cancelQuery(SessionContext session,
                 String resultId)
          throws SqlExecutionException

Cancels a table program and stops the result retrieval. Blocking until cancellation command has been sent to cluster.

Throws:

SqlExecutionException

executeUpdate

ProgramTargetDescriptor executeUpdate(SessionContext session,
                                      String statement)
                               throws SqlExecutionException

Submits a Flink SQL update statement such as INSERT INTO.

Parameters:

session - context in with the statement is executed

statement - SQL update statement (currently only INSERT INTO is supported)

Returns:

information about the target of the submitted Flink job

Throws:

SqlExecutionException

validateSession

void validateSession(SessionContext session)
              throws SqlExecutionException

Validates the current session. For example, it checks whether all views are still valid.

Throws:

SqlExecutionException

stop

void stop(SessionContext session)

Stops the executor.