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

java.lang.Object
  extended by org.apache.hadoop.hive.ql.exec.Operator<TableScanDesc>
      extended by org.apache.hadoop.hive.ql.exec.TableScanOperator
All Implemented Interfaces:
Serializable, Node

public class TableScanOperator
extends Operator<TableScanDesc>
implements Serializable

Table Scan Operator If the data is coming from the map-reduce framework, just forward it. This will be needed as part of local work when data is not being read as part of map-reduce framework

See Also:
Serialized Form

Nested Class Summary
 
Nested classes/interfaces inherited from class org.apache.hadoop.hive.ql.exec.Operator
Operator.OperatorFunc, Operator.ProgressCounter, Operator.State
 
Field Summary
 
Fields inherited from class org.apache.hadoop.hive.ql.exec.Operator
alias, beginTime, childOperators, childOperatorsArray, childOperatorsTag, colExprMap, conf, counterNames, counterNameToEnum, counters, done, fatalErrorCntr, groupKeyObject, id, inputObjInspectors, inputRows, LOG, numInputRowsCntr, numOutputRowsCntr, operatorId, out, outputObjInspector, outputRows, parentOperators, reporter, state, statsMap, timeTakenCntr, totalTime
 
Constructor Summary
TableScanOperator()
           
 
Method Summary
 String getName()
          The operator name for this operator type.
 ArrayList<Integer> getNeededColumnIDs()
           
 int getType()
          Should be overridden to return the type of the specific operator among the types in OperatorType.
 void processOp(Object row, int tag)
          Currently, the table scan operator does not do anything special other than just forwarding the row.
 void setNeededColumnIDs(ArrayList<Integer> orign_columns)
           
 
Methods inherited from class org.apache.hadoop.hive.ql.exec.Operator
allInitializedParentsAreClosed, areAllParentsInitialized, assignCounterNameToEnum, augmentPlan, checkFatalErrors, close, closeOp, dump, dump, endGroup, fatalErrorMessage, forward, getChildOperators, getChildren, getColumnExprMap, getConf, getCounterNames, getCounterNameToEnum, getCounters, getDone, getExecContext, getGroupKeyObject, getIdentifier, getOperatorId, getParentOperators, getSchema, getStats, incrCounter, initEvaluators, initEvaluatorsAndReturnStruct, initialize, initializeChildren, initializeCounters, initializeLocalWork, initializeOp, initOperatorId, jobClose, logStats, passExecContext, preorderMap, process, removeChild, replaceChild, replaceParent, resetId, resetLastEnumUsed, resetStats, setAlias, setChildOperators, setColumnExprMap, setConf, setCounterNames, setCounterNameToEnum, setDone, setExecContext, setGroupKeyObject, setId, setOperatorId, setOutputCollector, setParentOperators, setReporter, setSchema, startGroup, updateCounters
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

TableScanOperator

public TableScanOperator()
Method Detail

processOp

public void processOp(Object row,
                      int tag)
               throws HiveException
Currently, the table scan operator does not do anything special other than just forwarding the row. Since the table data is always read as part of the map-reduce framework by the mapper. But, this assumption is not true, i.e table data is not only read by the mapper, this operator will be enhanced to read the table.

Specified by:
processOp in class Operator<TableScanDesc>
Parameters:
row - The object representing the row.
tag - The tag of the row usually means which parent this row comes from. Rows with the same tag should have exactly the same rowInspector all the time.
Throws:
HiveException

getName

public String getName()
The operator name for this operator type. This is used to construct the rule for an operator

Specified by:
getName in interface Node
Overrides:
getName in class Operator<TableScanDesc>
Returns:
the operator name

setNeededColumnIDs

public void setNeededColumnIDs(ArrayList<Integer> orign_columns)

getNeededColumnIDs

public ArrayList<Integer> getNeededColumnIDs()

getType

public int getType()
Description copied from class: Operator
Should be overridden to return the type of the specific operator among the types in OperatorType.

Overrides:
getType in class Operator<TableScanDesc>
Returns:
OperatorType.* or -1 if not overridden


Copyright © 2010 The Apache Software Foundation