org.apache.hadoop.hive.ql.exec
Class TableScanOperator
java.lang.Object
org.apache.hadoop.hive.ql.exec.Operator<tableScanDesc>
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
Fields inherited from class org.apache.hadoop.hive.ql.exec.Operator |
alias, childOperators, childOperatorsArray, childOperatorsTag, colExprMap, conf, done, id, inputObjInspectors, LOG, out, outputObjInspector, parentOperators, reporter, state, statsMap |
Methods inherited from class org.apache.hadoop.hive.ql.exec.Operator |
areAllParentsInitialized, close, closeOp, dump, endGroup, forward, getChildOperators, getChildren, getColumnExprMap, getConf, getDone, getIdentifier, getParentOperators, getSchema, getStats, initEvaluators, initEvaluatorsAndReturnStruct, initialize, initializeChildren, initializeOp, jobClose, logStats, preorderMap, removeChild, replaceChild, replaceParent, resetStats, setAlias, setChildOperators, setColumnExprMap, setConf, setDone, setId, setOutputCollector, setParentOperators, setReporter, setSchema, startGroup |
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
TableScanOperator
public TableScanOperator()
process
public void process(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:
process
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()
Copyright © 2009 The Apache Software Foundation