JoinResultSet (Apache Derby V10.14 Internals)

java.lang.Object
- org.apache.derby.impl.sql.execute.BasicNoPutResultSetImpl
- - org.apache.derby.impl.sql.execute.NoPutResultSetImpl
  - - org.apache.derby.impl.sql.execute.JoinResultSet

All Implemented Interfaces:

CursorResultSet, NoPutResultSet, ResultSet, RowLocationRetRowSource, RowSource

Direct Known Subclasses:

MergeJoinResultSet, NestedLoopJoinResultSet
```
abstract class JoinResultSet
extends NoPutResultSetImpl
implements CursorResultSet
```
Takes 2 NoPutResultSets and a join filter and returns the join's rows satisfying the filter as a result set.

Nested Class Summary
- Nested classes/interfaces inherited from class org.apache.derby.impl.sql.execute.BasicNoPutResultSetImpl
  BasicNoPutResultSetImpl.FieldComparator

Field Summary

Fields
Modifier and Type	Field	Description
`protected boolean`	`isRightOpen`
`protected int`	`leftNumCols`
`NoPutResultSet`	`leftResultSet`
`protected ExecRow`	`leftRow`
`protected ExecRow`	`mergedRow`
`boolean`	`notExistsRightSide`
`boolean`	`oneRowRightSide`
`protected GeneratedMethod`	`restriction`
`long`	`restrictionTime`
`protected int`	`rightNumCols`
`NoPutResultSet`	`rightResultSet`
`protected ExecRow`	`rightRow`
`int`	`rowsReturned`
`int`	`rowsSeenLeft`
`int`	`rowsSeenRight`
`(package private) java.lang.String`	`userSuppliedOptimizerOverrides`

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.execute.NoPutResultSet
ABSOLUTE, FIRST, LAST, NEXT, PREVIOUS, RELATIVE, TEMPORARY_RESULT_SET_NUMBER

Fields inherited from class org.apache.derby.impl.sql.execute.NoPutResultSetImpl
checkNullCols, clonedExecRow, cncLen, resultSetNumber, targetResultSet

Fields inherited from interface org.apache.derby.iapi.sql.ResultSet
CURRENT_RESULTSET_ONLY, ENTIRE_RESULTSET_TREE, ISAFTERLAST, ISBEFOREFIRST, ISFIRST, ISLAST

Constructor Summary

Constructors
Constructor	Description
`JoinResultSet(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

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	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.
`protected void`	`closeRight()`	close the rightResultSet
`void`	`finish()`	Tells the system that there will be no more access to any database information via this result set; in particular, no more calls to open().
`ExecRow`	`getCurrentRow()`	A join is combining rows from two sources, so it should never be used in a positioned update or delete.
`RowLocation`	`getRowLocation()`	A join is combining rows from two sources, so it has no single row location to return; just return a null.
`void`	`openCore()`	open a scan on the join.
`protected void`	`openRight()`	open the rightResultSet.
`void`	`reopenCore()`	reopen a a join.

Methods inherited from class org.apache.derby.impl.sql.execute.BasicNoPutResultSetImpl
addWarning, attachStatementContext, checkCancellationFlag, checkRowPosition, childrenToXML, cleanUp, dumpTimeStats, finishAndRTS, getAbsoluteRow, getActivation, getAutoGeneratedKeysResultset, getBeginExecutionTimestamp, getCompactRow, getCurrentTimeMillis, getElapsedMillis, getEndExecutionTimestamp, getEstimatedRowCount, getExecuteTime, getExecutionFactory, getFirstRow, getLanguageConnectionContext, getLastRow, getNextRow, getNextRowCore, getPointOfAttachment, getPreviousRow, getRelativeRow, getRowNumber, getScanIsolationLevel, getSubqueryTrackingArray, getTransactionController, getWarnings, isClosed, isXplainOnlyMode, markAsTopResultSet, modifiedRowCount, open, recordConstructorTime, requiresRelocking, returnsRows, setAfterLastRow, setBeforeFirstRow, setCompactRow, setCompatRow, toXML, toXML

Methods inherited from class org.apache.derby.impl.sql.execute.NoPutResultSetImpl
clearCurrentRow, clearOrderableCache, closeRowSource, getCursorName, getNextRowFromRowSource, getResultDescription, getValidColumns, isForUpdate, markRowAsDeleted, needsRowLocation, needsRowLocationForDeferredCheckConstraints, needsToClone, offendingRowLocation, positionScanAtRowLocation, printQualifiers, resultSetNumber, rowLocation, setCurrentRow, setHasDeferrableChecks, setNeedsRowLocation, setTargetResultSet, skipRow, skipScan, unpackHashValue, updateRow

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, getTimeSpent, getWarnings, isClosed, modifiedRowCount, open, returnsRows, setAfterLastRow, setBeforeFirstRow, toXML

- Field Detail
  - rowsSeenLeft
```
public int rowsSeenLeft
```
  - rowsSeenRight
```
public int rowsSeenRight
```
  - rowsReturned
```
public int rowsReturned
```
  - restrictionTime
```
public long restrictionTime
```
  - isRightOpen
```
protected boolean isRightOpen
```
  - leftRow
```
protected ExecRow leftRow
```
  - rightRow
```
protected ExecRow rightRow
```
  - mergedRow
```
protected ExecRow mergedRow
```
  - leftResultSet
```
public NoPutResultSet leftResultSet
```
  - leftNumCols
```
protected int leftNumCols
```
  - rightResultSet
```
public NoPutResultSet rightResultSet
```
  - rightNumCols
```
protected int rightNumCols
```
  - restriction
```
protected GeneratedMethod restriction
```
  - oneRowRightSide
```
public boolean oneRowRightSide
```
  - notExistsRightSide
```
public boolean notExistsRightSide
```
  - userSuppliedOptimizerOverrides
```
java.lang.String userSuppliedOptimizerOverrides
```
- Constructor Detail
  - JoinResultSet
```
JoinResultSet(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()
  - openCore
```
public void openCore()
              throws StandardException
```
    open a scan on the join. For a join, this means: o Open the left ResultSet o Do a getNextRow() on the left ResultSet to establish a position and get "parameter values" for the right ResultSet. NOTE: It is possible for the getNextRow() to return null, in which case there is no need to open the RightResultSet. We must remember this condition. o If the getNextRow() on the left ResultSet succeeded, then open() the right ResultSet. scan parameters are evaluated at each open, so there is probably some way of altering their values...
    
    Specified by:
    
    openCore in interface NoPutResultSet
    
    Throws:
    
    StandardException - Thrown on error
  - reopenCore
```
public void reopenCore()
                throws StandardException
```
    reopen a a join.
    
    Specified by:
    
    reopenCore in interface NoPutResultSet
    
    Overrides:
    
    reopenCore in class BasicNoPutResultSetImpl
    
    Throws:
    
    StandardException - thrown if cursor finished.
    
    See Also:
    
    NoPutResultSet.openCore()
  - close
```
public void close()
           throws StandardException
```
    If the result set has been opened, close the open scan. WARNING does not track close time, since it is expected to be called directly by its subclasses, and we don't want to skew the times
    
    Specified by:
    
    close in interface ResultSet
    
    Overrides:
    
    close in class NoPutResultSetImpl
    
    Throws:
    
    StandardException - thrown on error
  - finish
```
public void finish()
            throws StandardException
```
    Description copied from interface: ResultSet
    
    Tells the system that there will be no more access to any database information via this result set; in particular, no more calls to open(). Will close the result set if it is not already closed.
    
    Specified by:
    
    finish in interface ResultSet
    
    Overrides:
    
    finish in class BasicNoPutResultSetImpl
    
    Throws:
    
    StandardException - on error
  - getRowLocation
```
public RowLocation getRowLocation()
```
    A join is combining rows from two sources, so it has no single row location to return; just return a null.
    
    Specified by:
    
    getRowLocation in interface CursorResultSet
    
    Returns:
    
    the row location of the current cursor row.
    
    See Also:
    
    CursorResultSet
  - getCurrentRow
```
public ExecRow getCurrentRow()
```
    A join is combining rows from two sources, so it should never be used in a positioned update or delete.
    
    Specified by:
    
    getCurrentRow in interface CursorResultSet
    
    Returns:
    
    a null value.
    
    See Also:
    
    CursorResultSet
  - openRight
```
protected void openRight()
                  throws StandardException
```
    open the rightResultSet. If already open, just reopen.
    
    Throws:
    
    StandardException - Thrown on error
  - closeRight
```
protected void closeRight()
                   throws StandardException
```
    close the rightResultSet
    
    Throws:
    
    StandardException

Class JoinResultSet

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.derby.impl.sql.execute.BasicNoPutResultSetImpl

Field Summary

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

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

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

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

Constructor Summary

Method Summary

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

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

Methods inherited from class java.lang.Object

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

Field Detail

rowsSeenLeft

rowsSeenRight

rowsReturned

restrictionTime

isRightOpen

leftRow

rightRow

mergedRow

leftResultSet

leftNumCols

rightResultSet

rightNumCols

restriction

oneRowRightSide

notExistsRightSide

userSuppliedOptimizerOverrides

Constructor Detail

JoinResultSet

Method Detail

clearScanState

openCore

reopenCore

close

finish

getRowLocation

getCurrentRow

openRight

closeRight