org.apache.derby.impl.sql.execute

Class NestedLoopJoinResultSet

java.lang.Object

org.apache.derby.impl.sql.execute.BasicNoPutResultSetImpl

org.apache.derby.impl.sql.execute.NoPutResultSetImpl

org.apache.derby.impl.sql.execute.JoinResultSet

org.apache.derby.impl.sql.execute.NestedLoopJoinResultSet

All Implemented Interfaces:

CursorResultSet, NoPutResultSet, ResultSet, RowLocationRetRowSource, RowSource

Direct Known Subclasses:

HashJoinResultSet, NestedLoopLeftOuterJoinResultSet

class NestedLoopJoinResultSet
extends JoinResultSet

Takes 2 NoPutResultSets and a join filter and returns the join's rows satisfying the filter as a result set.

Field Summary

Fields

Modifier and Type	Field and Description
private boolean	returnedRowMatchingRightSide
private ExecRow	rightTemplate

Fields inherited from class org.apache.derby.impl.sql.execute.JoinResultSet

isRightOpen, leftNumCols, leftResultSet, leftRow, mergedRow, notExistsRightSide, oneRowRightSide, restriction, restrictionTime, rightNumCols, rightResultSet, rightRow, rowsReturned, rowsSeenLeft, rowsSeenRight, userSuppliedOptimizerOverrides

Fields inherited from class org.apache.derby.impl.sql.execute.NoPutResultSetImpl

checkNullCols, clonedExecRow, cncLen, resultSetNumber, targetResultSet

Fields inherited from class org.apache.derby.impl.sql.execute.BasicNoPutResultSetImpl

activation, beginTime, closeTime, compactRow, constructorTime, currentRow, endExecutionTime, finished, isOpen, isTopResultSet, nextTime, numOpens, openTime, optimizerEstimatedCost, optimizerEstimatedRowCount, resultDescription, rowsFiltered, rowsSeen, startExecutionTime, subqueryTrackingArray

Fields inherited from interface org.apache.derby.iapi.sql.ResultSet

CURRENT_RESULTSET_ONLY, ENTIRE_RESULTSET_TREE, ISAFTERLAST, ISBEFOREFIRST, ISFIRST, ISLAST

Fields inherited from interface org.apache.derby.iapi.sql.execute.NoPutResultSet

ABSOLUTE, FIRST, LAST, NEXT, PREVIOUS, RELATIVE

Constructor Summary

Constructors

Constructor and Description
NestedLoopJoinResultSet(NoPutResultSet leftResultSet, int leftNumCols, NoPutResultSet rightResultSet, int rightNumCols, Activation activation, GeneratedMethod restriction, int resultSetNumber, boolean oneRowRightSide, boolean notExistsRightSide, double optimizerEstimatedRowCount, double optimizerEstimatedCost, java.lang.String userSuppliedOptimizerOverrides)

Method Summary

Modifier and Type	Method and Description
(package private) void	clearScanState() Clear any private state that changes during scans.
void	close() If the result set has been opened, close the open scan.
ExecRow	getNextRowCore() Return the requested values computed from the next row (if any) for which the restriction evaluates to true.
long	getTimeSpent(int type) Return the total amount of time spent in this ResultSet

Methods inherited from class org.apache.derby.impl.sql.execute.JoinResultSet

closeRight, finish, getCurrentRow, getRowLocation, openCore, openRight, reopenCore

Methods inherited from class org.apache.derby.impl.sql.execute.NoPutResultSetImpl

clearCurrentRow, clearOrderableCache, closeRowSource, getCursorName, getNextRowFromRowSource, getResultDescription, getValidColumns, isForUpdate, markRowAsDeleted, needsRowLocation, needsToClone, positionScanAtRowLocation, printQualifiers, resultSetNumber, rowLocation, setCurrentRow, setNeedsRowLocation, setTargetResultSet, skipRow, skipScan, updateRow

Methods inherited from class org.apache.derby.impl.sql.execute.BasicNoPutResultSetImpl

addWarning, attachStatementContext, checkCancellationFlag, checkRowPosition, cleanUp, dumpTimeStats, finishAndRTS, getAbsoluteRow, getActivation, getAutoGeneratedKeysResultset, getBeginExecutionTimestamp, getCompactRow, getCurrentTimeMillis, getElapsedMillis, getEndExecutionTimestamp, getEstimatedRowCount, getExecuteTime, getExecutionFactory, getFirstRow, getLanguageConnectionContext, getLastRow, getNextRow, getPointOfAttachment, getPreviousRow, getRelativeRow, getRowNumber, getScanIsolationLevel, getSubqueryTrackingArray, getTransactionController, getWarnings, isClosed, isXplainOnlyMode, markAsTopResultSet, modifiedRowCount, open, recordConstructorTime, requiresRelocking, returnsRows, setAfterLastRow, setBeforeFirstRow, setCompactRow, setCompatRow

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.derby.iapi.sql.ResultSet

addWarning, checkRowPosition, cleanUp, clearCurrentRow, getAbsoluteRow, getActivation, getAutoGeneratedKeysResultset, getBeginExecutionTimestamp, getCursorName, getEndExecutionTimestamp, getExecuteTime, getFirstRow, getLastRow, getNextRow, getPreviousRow, getRelativeRow, getResultDescription, getRowNumber, getSubqueryTrackingArray, getWarnings, isClosed, modifiedRowCount, open, returnsRows, setAfterLastRow, setBeforeFirstRow

Field Detail

returnedRowMatchingRightSide

private boolean returnedRowMatchingRightSide

rightTemplate

private ExecRow rightTemplate

Constructor Detail

NestedLoopJoinResultSet

NestedLoopJoinResultSet(NoPutResultSet leftResultSet,
                        int leftNumCols,
                        NoPutResultSet rightResultSet,
                        int rightNumCols,
                        Activation activation,
                        GeneratedMethod restriction,
                        int resultSetNumber,
                        boolean oneRowRightSide,
                        boolean notExistsRightSide,
                        double optimizerEstimatedRowCount,
                        double optimizerEstimatedCost,
                        java.lang.String userSuppliedOptimizerOverrides)

Method Detail

clearScanState

void clearScanState()

Clear any private state that changes during scans. This includes things like the last row seen, etc. THis does not include immutable things that are typically set up in the constructor.

This method is called on open()/close() and reopen()

WARNING: this should be implemented in every sub class and it should always call super.clearScanState().

Overrides:

clearScanState in class JoinResultSet

getNextRowCore

public ExecRow getNextRowCore()
                       throws StandardException

Return the requested values computed from the next row (if any) for which the restriction evaluates to true.

restriction parameters are evaluated for each row.

Specified by:

getNextRowCore in interface NoPutResultSet

Specified by:

getNextRowCore in class BasicNoPutResultSetImpl

Returns:

the next row in the join result

Throws:

StandardException - Thrown on error

StandardException - ResultSetNotOpen thrown if closed

See Also:

NoPutResultSet.getNextRowCore()

close

public void close()
           throws StandardException

If the result set has been opened, close the open scan.

Specified by:

close in interface ResultSet

Overrides:

close in class JoinResultSet

Throws:

StandardException - thrown on error

getTimeSpent

public long getTimeSpent(int type)

Return the total amount of time spent in this ResultSet

Parameters:

type - CURRENT_RESULTSET_ONLY - time spent only in this ResultSet ENTIRE_RESULTSET_TREE - time spent in this ResultSet and below.

Returns:

long The total amount of time spent (in milliseconds).