com.metamatrix.query.processor.relational
Class NullNode

java.lang.Object
  com.metamatrix.query.processor.relational.RelationalNode
      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, getNodeStatistics, getParent, initialize, isBatchFull, isClosed, nextBatch, nodeToString, open, projectTuple, pullBatch, reset, 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