com.metamatrix.query.processor.relational
Class SelectNode

java.lang.Object
  com.metamatrix.query.processor.relational.RelationalNode
      com.metamatrix.query.processor.relational.SelectNode

All Implemented Interfaces:

Describable, java.lang.Cloneable

Direct Known Subclasses:

DependentSelectNode

public class SelectNode
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

SelectNode(int nodeID)

Method Summary

java.lang.Object	clone() All the implementation of Cloneable interface need to implement clone() method.
protected void	copy(SelectNode source, SelectNode target)
Criteria	getCriteria()
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.
void	open()
protected void	prepareToProcessTuple(java.util.Map elementMap, java.util.List currentTuple) This method is called by RelationalNode.nextBatch() just after the current tuple is pulled from the child processor node and just before any processing is done (in this case, before the criteria is evaluated).
void	reset()
void	setCriteria(Criteria criteria)

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, projectTuple, pullBatch, 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

SelectNode

public SelectNode(int nodeID)

Method Detail

reset

public void reset()

Overrides:

reset in class RelationalNode

setCriteria

public void setCriteria(Criteria criteria)

getCriteria

public Criteria getCriteria()

open

public void open()
          throws MetaMatrixComponentException,
                 MetaMatrixProcessingException

Overrides:

open in class RelationalNode

Throws:

MetaMatrixComponentException

MetaMatrixProcessingException

nextBatchDirect

public TupleBatch nextBatchDirect()
                           throws BlockedException,
                                  MetaMatrixComponentException,
                                  MetaMatrixProcessingException

Description copied from class: RelationalNode

Template method for subclasses to implement.

Specified by:

nextBatchDirect in class RelationalNode

Returns:

Throws:

BlockedException

MetaMatrixComponentException

MetaMatrixProcessingException - if exception related to user input occured

See Also:

RelationalNode.nextBatchDirect()

prepareToProcessTuple

protected void prepareToProcessTuple(java.util.Map elementMap,
                                     java.util.List currentTuple)
                              throws BlockedException,
                                     MetaMatrixComponentException,
                                     MetaMatrixProcessingException

This method is called by RelationalNode.nextBatch() just after the current tuple is pulled from the child processor node and just before any processing is done (in this case, before the criteria is evaluated). This gives subclasses a chance to do any custom processing - for example, to examine the current tuple in order to execute correlated subqueries.

Parameters:

elementMap - Map of ElementSymbol elements to Integer indices into the currentTuple parameter

currentTuple - the current tuple about to be processed by this node

Throws:

MetaMatrixProcessingException - for exception due to user input

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

copy

protected void copy(SelectNode source,
                    SelectNode target)

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