org.apache.hadoop.hive.ql.exec
Class ExplainTask

java.lang.Object
  org.apache.hadoop.hive.ql.exec.Task<ExplainWork>
      org.apache.hadoop.hive.ql.exec.ExplainTask

All Implemented Interfaces:

Serializable, Node

public class ExplainTask
extends Task<ExplainWork>
implements Serializable

ExplainTask implementation.

See Also:

Serialized Form

Nested Class Summary

static class

ExplainTask.MethodComparator MethodComparator.

Nested classes/interfaces inherited from class org.apache.hadoop.hive.ql.exec.Task

Task.FeedType

Field Summary

static String

EXPL_COLUMN_NAME

Fields inherited from class org.apache.hadoop.hive.ql.exec.Task

BACKUP_COMMON_JOIN, backupChildrenTasks, backupTask, childTasks, clonedConf, COMMON_JOIN, conf, console, CONVERTED_LOCAL_MAPJOIN, CONVERTED_MAPJOIN, db, driverContext, feedSubscribers, id, initialized, isdone, jobID, LOCAL_MAPJOIN, LOG, NO_TAG, parentTasks, queryPlan, queued, started, taskCounters, taskHandle, taskTag, work

Constructor Summary

ExplainTask()

Method Summary

int	execute(DriverContext driverContext) This method is overridden in each Task.
static org.json.JSONObject	getJSONPlan(PrintStream out, ExplainWork work)
String	getName() Gets the name of the node.
List<FieldSchema>	getResultSchema()
StageType	getType() Should be overridden to return the type of the specific task among the types in StageType.
protected void	localizeMRTmpFilesImpl(Context ctx) If this task uses any map-reduce intermediate data (either for reading or for writing), localize them (using the supplied Context).
static String	outputAST(String treeString, PrintStream out, boolean jsonOutput, int indent)
static org.json.JSONObject	outputDependencies(PrintStream out, boolean jsonOutput, List<Task<? extends Serializable>> rootTasks, int indent)
static org.json.JSONObject	outputStagePlans(PrintStream out, ExplainWork work, List<Task<? extends Serializable>> rootTasks, int indent)

Methods inherited from class org.apache.hadoop.hive.ql.exec.Task

addDependentTask, cloneConf, done, executeTask, fetch, getAndInitBackupTask, getBackupChildrenTasks, getBackupTask, getChildren, getChildTasks, getCounters, getDependentTasks, getFeedSubscribers, getId, getInitialized, getJobID, getParentTasks, getQueryPlan, getQueued, getReducer, getTaskTag, getTopOperators, getWork, hasReduce, ifRetryCmdWhenFail, initialize, isLocalMode, isMapRedLocalTask, isMapRedTask, isRunnable, localizeMRTmpFiles, pushFeed, receiveFeed, removeDependentTask, removeFromChildrenTasks, requireLock, setBackupChildrenTasks, setBackupTask, setChildTasks, setDone, setFeedSubscribers, setId, setInitialized, setLocalMode, setParentTasks, setQueryPlan, setQueued, setRetryCmdWhenFail, setStarted, setTaskTag, setWork, started, subscribeFeed

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

EXPL_COLUMN_NAME

public static final String EXPL_COLUMN_NAME

See Also:

Constant Field Values

Constructor Detail

ExplainTask

public ExplainTask()

Method Detail

getJSONPlan

public static org.json.JSONObject getJSONPlan(PrintStream out,
                                              ExplainWork work)
                                       throws Exception

Throws:

Exception

execute

public int execute(DriverContext driverContext)

Description copied from class: Task

This method is overridden in each Task. TODO execute should return a TaskHandle.

Specified by:

execute in class Task<ExplainWork>

Returns:

status of executing the task

outputAST

public static String outputAST(String treeString,
                               PrintStream out,
                               boolean jsonOutput,
                               int indent)
                        throws org.json.JSONException

Throws:

org.json.JSONException

outputDependencies

public static org.json.JSONObject outputDependencies(PrintStream out,
                                                     boolean jsonOutput,
                                                     List<Task<? extends Serializable>> rootTasks,
                                                     int indent)
                                              throws Exception

Throws:

Exception

outputStagePlans

public static org.json.JSONObject outputStagePlans(PrintStream out,
                                                   ExplainWork work,
                                                   List<Task<? extends Serializable>> rootTasks,
                                                   int indent)
                                            throws Exception

Throws:

Exception

getType

public StageType getType()

Description copied from class: Task

Should be overridden to return the type of the specific task among the types in StageType.

Specified by:

getType in class Task<ExplainWork>

Returns:

StageType.* or null if not overridden

getName

public String getName()

Description copied from interface: Node

Gets the name of the node. This is used in the rule dispatchers.

Specified by:

getName in interface Node

Returns:

String

localizeMRTmpFilesImpl

protected void localizeMRTmpFilesImpl(Context ctx)

Description copied from class: Task

If this task uses any map-reduce intermediate data (either for reading or for writing), localize them (using the supplied Context). Map-Reduce intermediate directories are allocated using Context.getMRTmpFileURI() and can be localized using localizeMRTmpFileURI(). This method is declared abstract to force any task code to explicitly deal with this aspect of execution.

Specified by:

localizeMRTmpFilesImpl in class Task<ExplainWork>

Parameters:

ctx - context object with which to localize

getResultSchema

public List<FieldSchema> getResultSchema()

Overrides:

getResultSchema in class Task<ExplainWork>