com.metamatrix.query.processor.relational
Class NullNode

java.lang.Object
  extended by com.metamatrix.query.processor.relational.RelationalNode
      extended by com.metamatrix.query.processor.relational.NullNode
All Implemented Interfaces:
Describable, java.lang.Cloneable

public class NullNode
extends RelationalNode


Field Summary
 
Fields inherited from interface com.metamatrix.query.processor.Describable
PROP_BINDINGS, PROP_CHILDREN, PROP_CONDITIONS, PROP_CRITERIA, PROP_DATA_COL, PROP_DEFAULT, PROP_DEFAULT_PROGRAM, PROP_ELSE, PROP_ENCODING, PROP_EXECUTION_PLAN, PROP_EXPRESSION, PROP_FORMATTED, PROP_GROUP, PROP_GROUP_COLS, PROP_IN_MEMORY, PROP_INTO_GROUP, PROP_IS_STAGING, PROP_JOIN_CRITERIA, PROP_JOIN_STRATEGY, PROP_JOIN_TYPE, PROP_MESSAGE, PROP_MODEL_NAME, PROP_NAMESPACE, PROP_NAMESPACE_DECL, PROP_NODE_COST_ESTIMATES, PROP_NODE_STATS_LIST, PROP_NODE_STATS_PROPS, PROP_OPTIONAL, PROP_OUTPUT_COLS, PROP_PROGRAM, PROP_PROGRAMS, PROP_RECURSE_DIR, PROP_REMOVE_DUPS, PROP_RESULT_SET, PROP_ROW_LIMIT, PROP_ROW_OFFSET, PROP_SELECT_COLS, PROP_SORT_COLS, PROP_SQL, PROP_TAG, PROP_THEN, PROP_TYPE, PROP_VARIABLE
 
Constructor Summary
NullNode(int nodeID)
           
 
Method Summary
 java.lang.Object clone()
          All the implementation of Cloneable interface need to implement clone() method.
 java.util.Map getDescriptionProperties()
          Get a description as a set of properties of primitive types such as String, Integer, etc.
protected  void getNodeString(java.lang.StringBuffer str)
           
 TupleBatch nextBatchDirect()
          Template method for subclasses to implement.
 
Methods inherited from class com.metamatrix.query.processor.relational.RelationalNode
addBatchRow, addChild, close, copy, createLookupMap, getBatchSize, getBufferManager, getChildDescriptionProperties, getChildPlans, getChildren, getClassName, getConnectionID, getContext, getDataManager, getElements, getEstimateNodeCardinality, getID, getLanguageObjects, getNodeStatistics, getParent, hasPendingRows, initialize, isBatchFull, isClosed, nextBatch, nodeToString, open, projectTuple, pullBatch, reset, setContext, setElements, setEstimateDepAccessCardinality, setEstimateDepJoinCost, setEstimateJoinCost, setEstimateNodeCardinality, setEstimateNodeSetSize, setID, setParent, terminateBatches, toString
 
Methods inherited from class java.lang.Object
equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

NullNode

public NullNode(int nodeID)
Method Detail

nextBatchDirect

public TupleBatch nextBatchDirect()
                           throws MetaMatrixComponentException
Description copied from class: RelationalNode
Template method for subclasses to implement.

Specified by:
nextBatchDirect in class RelationalNode
Returns:
Throws:
BlockedException
MetaMatrixComponentException

getNodeString

protected void getNodeString(java.lang.StringBuffer str)
Overrides:
getNodeString in class RelationalNode

clone

public java.lang.Object clone()
Description copied from class: RelationalNode
All the implementation of Cloneable interface need to implement clone() method. The plan is only clonable in the pre-execution stage, not the execution state (things like program state, result sets, etc). It's only safe to call that method in between query processings, in other words, it's only safe to call clone() on a plan after nextTuple() returns null, meaning the plan has finished processing.

Specified by:
clone in class RelationalNode

getDescriptionProperties

public java.util.Map getDescriptionProperties()
Description copied from interface: Describable
Get a description as a set of properties of primitive types such as String, Integer, etc.

Specified by:
getDescriptionProperties in interface Describable
Overrides:
getDescriptionProperties in class RelationalNode
Returns:
Map of properties


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