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org.apache.derby.impl.sql.compile
Class CurrentOfNode  

java.lang.Object
  org.apache.derby.impl.sql.compile.QueryTreeNode
      org.apache.derby.impl.sql.compile.ResultSetNode
          org.apache.derby.impl.sql.compile.FromTable
              org.apache.derby.impl.sql.compile.CurrentOfNode

All Implemented Interfaces:

org.apache.derby.iapi.sql.compile.Optimizable, org.apache.derby.iapi.sql.compile.Visitable

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public final class CurrentOfNode

extends FromTable

The CurrentOf operator is used by positioned DELETE and UPDATE to get the current row and location for the target cursor. The bind() operations for positioned DELETE and UPDATE add a column to the select list under the statement for the row location accessible from this node. This node is placed in the from clause of the select generated for the delete or update operation. It acts much like a FromBaseTable, using the information about the target table of the cursor to provide information.

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Field Summary
private  TableName	baseTableName
private  java.lang.String	cursorName
private  TableName	exposedTableName
private  org.apache.derby.iapi.sql.execute.ExecPreparedStatement	preStmt
private  org.apache.derby.iapi.sql.compile.CostEstimate	singleScanCostEstimate

 

Fields inherited from class org.apache.derby.impl.sql.compile.FromTable

bestAccessPath, bestCostEstimate, bestSortAvoidancePath, correlationName, corrTableName, currentAccessPath, hashKeyColumns, initialCapacity, level, loadFactor, maxCapacity, tableNumber, tableProperties, trulyTheBestAccessPath, userSpecifiedJoinStrategy

 

Fields inherited from class org.apache.derby.impl.sql.compile.ResultSetNode

costEstimate, cursorTargetTable, insertSource, optimizer, referencedTableMap, resultColumns, resultSetNumber, scratchCostEstimate, statementResultSet

 

Fields inherited from class org.apache.derby.impl.sql.compile.QueryTreeNode

AUTOINCREMENT_INC_INDEX, AUTOINCREMENT_IS_AUTOINCREMENT_INDEX, AUTOINCREMENT_START_INDEX, beginOffset, endOffset

 

Constructor Summary

CurrentOfNode()

 

Method Summary
void	bindExpressions(FromList fromListParam)           Bind the expressions in this ResultSetNode.
ResultSetNode	bindNonVTITables(org.apache.derby.iapi.sql.dictionary.DataDictionary dataDictionary, FromList fromListParam)           Binding this FromTable means finding the prepared statement for the cursor and creating the result columns (the columns updatable on that cursor).
org.apache.derby.iapi.sql.compile.CostEstimate	estimateCost(org.apache.derby.iapi.sql.compile.OptimizablePredicateList predList, org.apache.derby.iapi.sql.dictionary.ConglomerateDescriptor cd, org.apache.derby.iapi.sql.compile.CostEstimate outerCost, org.apache.derby.iapi.sql.compile.Optimizer optimizer, org.apache.derby.iapi.sql.compile.RowOrdering rowOrdering)           Estimate the cost of scanning this Optimizable using the given predicate list with the given conglomerate.
void	generate(ActivationClassBuilder acb, org.apache.derby.iapi.services.compiler.MethodBuilder mb)           Generation on a CurrentOfNode creates a scan on the cursor, CurrentOfResultSet.
TableName	getBaseCursorTargetTableName()
java.lang.String	getCursorName()
(package private)  org.apache.derby.iapi.sql.execute.ExecPreparedStatement	getCursorStatement()           Return the CursorNode associated with a positioned update/delete.
java.lang.String	getExposedName()           Get the exposed name for this table, which is the name that can be used to refer to it in the rest of the query.
TableName	getExposedTableName()
ResultColumn	getMatchingColumn(ColumnReference columnReference)           Try to find a ResultColumn in the table represented by this CurrentOfNode that matches the name in the given ColumnReference.
void	init(java.lang.Object cursor, java.lang.Object tableProperties)           Initializer for a table in a FROM list.
ResultSetNode	optimize(org.apache.derby.iapi.sql.dictionary.DataDictionary dataDictionary, PredicateList predicateList, double outerRows)           Optimize this CurrentOfNode.
ResultSetNode	preprocess(int numTables, GroupByList gbl, FromList fromList)           Preprocess a CurrentOfNode.
void	printSubNodes(int depth)           Prints the sub-nodes of this object.
java.lang.String	toString()           Convert this object to a String.
int	updateTargetLockMode()           Get the lock mode for this table as the target of an update statement (a delete or update).

 

Methods inherited from class org.apache.derby.impl.sql.compile.FromTable

areAllColumnsProjected, assignCostEstimate, canBeOrdered, considerSortAvoidancePath, convertAbsoluteToRelativeColumnPosition, cursorTargetTable, decrementLevel, feasibleJoinStrategy, fillInReferencedTableMap, flatten, forUpdate, getBaseTableName, getBestAccessPath, getBestSortAvoidancePath, getCostEstimate, getCurrentAccessPath, getFromTableByName, getLevel, getName, getNumColumnsReturned, getProperties, getResultColumnsForList, getSchemaDescriptor, getSchemaDescriptor, getScratchCostEstimate, getTableDescriptor, getTableName, getTableNumber, getTrulyTheBestAccessPath, getUserSpecifiedJoinStrategy, hashKeyColumns, hasTableNumber, initAccessPaths, initialCapacity, isBaseTable, isCoveringIndex, isFlattenableJoinNode, isMaterializable, isOneRowScan, isTargetTable, legalJoinOrder, loadFactor, LOJ_reorderable, markUpdatableByCursor, maxCapacity, memoryUsageOK, modifyAccessPath, needsSpecialRCLBinding, nextAccessPath, optimizeIt, optimizeSubqueries, pullOptPredicates, pushExpressions, pushOptPredicate, rememberAsBest, rememberJoinStrategyAsBest, rememberSortAvoidancePath, resetJoinStrategies, setAllColumnsProjected, setCostEstimate, setHashKeyColumns, setLevel, setProperties, setTableNumber, startOptimizing, supportsMultipleInstantiations, tellRowOrderingAboutConstantColumns, transformOuterJoins, uniqueJoin, verifyProperties

 

Methods inherited from class org.apache.derby.impl.sql.compile.ResultSetNode

accept, addNewPredicate, assignResultSetNumber, bindExpressionsWithTables, bindResultColumns, bindResultColumns, bindTargetExpressions, bindUntypedNullsToResultColumns, bindVTITables, changeAccessPath, closeMethodArgument, columnTypesAndLengthsMatch, considerMaterialization, enhanceRCLForInsert, ensurePredicateList, flattenableInFromSubquery, generateNormalizationResultSet, generateResultSet, genNewRCForInsert, genNormalizeResultSetNode, genProjectRestrict, genProjectRestrict, genProjectRestrictForReordering, getAllResultColumns, getCostEstimate, getCursorTargetTable, getFinalCostEstimate, getFromList, getNewCostEstimate, getOptimizer, getReferencedTableMap, getResultColumns, getResultSetNumber, isNotExists, isOneRowResultSet, isOrderedOn, isPossibleDistinctScan, isUpdatableCursor, LOJgetReferencedTables, makeResultDescription, makeResultDescriptors, markAsCursorTargetTable, markForDistinctScan, markOrderingDependent, markStatementResultSet, modifyAccessPaths, notCursorTargetTable, notFlattenableJoin, numDistinctAggregates, parseDefault, performMaterialization, projectResultColumns, pushOrderByList, referencesTarget, rejectParameters, rejectXMLValues, renameGeneratedResultNames, replaceDefaults, returnsAtMostOneRow, setInsertSource, setReferencedTableMap, setResultColumns, setResultToBooleanTrueNode, setTableConstructorTypes, subqueryReferencesTarget, verifySelectStarSubquery

 

Methods inherited from class org.apache.derby.impl.sql.compile.QueryTreeNode

bind, convertDefaultNode, debugFlush, debugPrint, executeSchemaName, executeStatementName, formatNodeString, foundString, generate, generateAuthorizeCheck, getBeginOffset, getClassFactory, getCompilerContext, getContextManager, getCursorInfo, getDataDictionary, getDependencyManager, getEndOffset, getExecutionFactory, getGenericConstantActionFactory, getIntProperty, getLanguageConnectionContext, getNodeFactory, getNodeType, getNullNode, getParameterTypes, getRowEstimate, getSchemaDescriptor, getSchemaDescriptor, getSPSName, getStatementType, getTableDescriptor, getTypeCompiler, init, init, init, init, init, init, init, init, init, init, init, init, init, isAtomic, isInstanceOf, isSessionSchema, isSessionSchema, makeConstantAction, makeTableName, needsSavepoint, nodeHeader, optimize, parseQueryText, printLabel, referencesSessionSchema, resolveTableToSynonym, setBeginOffset, setContextManager, setEndOffset, setNodeType, setRefActionInfo, treePrint, treePrint, verifyClassExist

 

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

 

Methods inherited from interface org.apache.derby.iapi.sql.compile.Optimizable

getDataDictionary, getReferencedTableMap, getResultSetNumber

 

Field Detail

cursorName

private java.lang.String cursorName

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preStmt

private org.apache.derby.iapi.sql.execute.ExecPreparedStatement preStmt

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exposedTableName

private TableName exposedTableName

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baseTableName

private TableName baseTableName

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singleScanCostEstimate

private org.apache.derby.iapi.sql.compile.CostEstimate singleScanCostEstimate

Constructor Detail

CurrentOfNode

public CurrentOfNode()

Method Detail

init

public void init(java.lang.Object cursor,
                 java.lang.Object tableProperties)

Description copied from class: FromTable

Initializer for a table in a FROM list.

Overrides:

init in class FromTable

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estimateCost

public org.apache.derby.iapi.sql.compile.CostEstimate estimateCost(org.apache.derby.iapi.sql.compile.OptimizablePredicateList predList,
                                                                   org.apache.derby.iapi.sql.dictionary.ConglomerateDescriptor cd,
                                                                   org.apache.derby.iapi.sql.compile.CostEstimate outerCost,
                                                                   org.apache.derby.iapi.sql.compile.Optimizer optimizer,
                                                                   org.apache.derby.iapi.sql.compile.RowOrdering rowOrdering)
                                                            throws org.apache.derby.iapi.error.StandardException

Description copied from interface: org.apache.derby.iapi.sql.compile.Optimizable

Estimate the cost of scanning this Optimizable using the given predicate list with the given conglomerate. It is assumed that the predicate list has already been classified. This cost estimate is just for one scan, not for the life of the query.

Specified by:

estimateCost in interface org.apache.derby.iapi.sql.compile.Optimizable

Overrides:

estimateCost in class FromTable

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bindNonVTITables

public ResultSetNode bindNonVTITables(org.apache.derby.iapi.sql.dictionary.DataDictionary dataDictionary,
                                      FromList fromListParam)
                               throws org.apache.derby.iapi.error.StandardException

Binding this FromTable means finding the prepared statement for the cursor and creating the result columns (the columns updatable on that cursor). We expect someone else to verify that the target table of the positioned update or delete is the table under this cursor.

Overrides:

bindNonVTITables in class ResultSetNode

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bindExpressions

public void bindExpressions(FromList fromListParam)

Bind the expressions in this ResultSetNode. This means binding the sub-expressions, as well as figuring out what the return type is for each expression.

Overrides:

bindExpressions in class ResultSetNode

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getMatchingColumn

public ResultColumn getMatchingColumn(ColumnReference columnReference)
                               throws org.apache.derby.iapi.error.StandardException

Try to find a ResultColumn in the table represented by this CurrentOfNode that matches the name in the given ColumnReference.

Overrides:

getMatchingColumn in class ResultSetNode

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preprocess

public ResultSetNode preprocess(int numTables,
                                GroupByList gbl,
                                FromList fromList)
                         throws org.apache.derby.iapi.error.StandardException

Preprocess a CurrentOfNode. For a CurrentOfNode, this simply means allocating a referenced table map to avoid downstream NullPointerExceptions. NOTE: There are no bits set in the referenced table map.

Overrides:

preprocess in class ResultSetNode

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optimize

public ResultSetNode optimize(org.apache.derby.iapi.sql.dictionary.DataDictionary dataDictionary,
                              PredicateList predicateList,
                              double outerRows)
                       throws org.apache.derby.iapi.error.StandardException

Optimize this CurrentOfNode. Nothing to do.

Overrides:

optimize in class ResultSetNode

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generate

public void generate(ActivationClassBuilder acb,
                     org.apache.derby.iapi.services.compiler.MethodBuilder mb)
              throws org.apache.derby.iapi.error.StandardException

Generation on a CurrentOfNode creates a scan on the cursor, CurrentOfResultSet.

This routine will generate and return a call of the form:

                ResultSetFactory.getCurrentOfResultSet(cursorName)
           

Overrides:

generate in class QueryTreeNode

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printSubNodes

public void printSubNodes(int depth)

Prints the sub-nodes of this object. See QueryTreeNode.java for how tree printing is supposed to work.

Overrides:

printSubNodes in class ResultSetNode

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toString

public java.lang.String toString()

Convert this object to a String. See comments in QueryTreeNode.java for how this should be done for tree printing.

Overrides:

toString in class FromTable

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getExposedName

public java.lang.String getExposedName()

Description copied from class: FromTable

Get the exposed name for this table, which is the name that can be used to refer to it in the rest of the query.

Overrides:

getExposedName in class FromTable

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getExposedTableName

public TableName getExposedTableName()

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getBaseCursorTargetTableName

public TableName getBaseCursorTargetTableName()

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getCursorName

public java.lang.String getCursorName()

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getCursorStatement

org.apache.derby.iapi.sql.execute.ExecPreparedStatement getCursorStatement()

Return the CursorNode associated with a positioned update/delete.

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updateTargetLockMode

public int updateTargetLockMode()

Get the lock mode for this table as the target of an update statement (a delete or update). This is implemented only for base tables and CurrentOfNodes.

Overrides:

updateTargetLockMode in class ResultSetNode

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Overview  Package   Class  Use  Deprecated  Index
Home >> All >> org >> apache >> derby >> impl >> sql >> [ compile overview ]	PREV CLASS  NEXT CLASS
SUMMARY:  JAVADOC |  SOURCE |  DOWNLOAD | NESTED | FIELD | CONSTR | METHOD	DETAIL: FIELD | CONSTR | METHOD

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