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

All Implemented Interfaces:

CursorResultSet, NoPutResultSet, ResultSet, RowLocationRetRowSource, RowSource

Direct Known Subclasses:

DistinctScanResultSet
```
public class HashScanResultSet
extends ScanResultSet
implements CursorResultSet
```
Takes a conglomerate and a table filter builds a hash table on the specified column of the conglomerate on the 1st open. Look up into the hash table is done on the hash key column. The hash table consists of either DataValueDescriptor[]s or Lists of DataValueDescriptor[]. The store builds the hash table. When a collision occurs, the store builds a List with the colliding DataValueDescriptor[]s.

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 ExecRow`	`compactRow`
`private long`	`conglomId`
`static int`	`DEFAULT_INITIAL_CAPACITY`
`static float`	`DEFAULT_LOADFACTOR`
`static int`	`DEFAULT_MAX_CAPACITY`
`protected boolean`	`eliminateDuplicates`
`private java.util.List`	`entryVector`
`private int`	`entryVectorSize`
`protected boolean`	`firstNext`
`boolean`	`forUpdate`
`protected BackingStoreHashtable`	`hashtable`
`private boolean`	`hashtableBuilt`
`int`	`hashtableSize`
`private int`	`initialCapacity`
`boolean`	`isConstraint`
`private boolean`	`keepAfterCommit`
`int[]`	`keyColumns`
`private float`	`loadFactor`
`private int`	`maxCapacity`
`Qualifier[][]`	`nextQualifiers`
`private int`	`numFetchedOnNext`
`private boolean`	`runTimeStatisticsOn`
`private boolean`	`sameStartStopPosition`
`java.util.Properties`	`scanProperties`
`Qualifier[][]`	`scanQualifiers`
`protected StaticCompiledOpenConglomInfo`	`scoci`
`private boolean`	`skipNullKeyColumns`
`private GeneratedMethod`	`startKeyGetter`
`private ExecIndexRow`	`startPosition`
`java.lang.String`	`startPositionString`
`private int`	`startSearchOperator`
`private GeneratedMethod`	`stopKeyGetter`
`private ExecIndexRow`	`stopPosition`
`java.lang.String`	`stopPositionString`
`private int`	`stopSearchOperator`
`java.lang.String`	`userSuppliedOptimizerOverrides`

Fields inherited from class org.apache.derby.impl.sql.execute.ScanResultSet
accessedCols, candidate, fetchRowLocations, indexName, isolationLevel, lockMode, resultRowBuilder, tableName

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

Constructor Summary

Constructors
Constructor	Description
HashScanResultSet(long conglomId, StaticCompiledOpenConglomInfo scoci, Activation activation, int resultRowTemplate, int resultSetNumber, GeneratedMethod startKeyGetter, int startSearchOperator, GeneratedMethod stopKeyGetter, int stopSearchOperator, boolean sameStartStopPosition, Qualifier[][] scanQualifiers, Qualifier[][] nextQualifiers, int initialCapacity, float loadFactor, int maxCapacity, int hashKeyItem, java.lang.String tableName, java.lang.String userSuppliedOptimizerOverrides, java.lang.String indexName, boolean isConstraint, boolean forUpdate, int colRefItem, int lockMode, boolean tableLocked, int isolationLevel, boolean skipNullKeyColumns, double optimizerEstimatedRowCount, double optimizerEstimatedCost)

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`(package private) boolean`	`canGetInstantaneousLocks()`	Can we get instantaneous locks when getting share row locks at READ COMMITTED.
`void`	`close()`	If the result set has been opened, close the open scan.
`ExecRow`	`getCurrentRow()`	This result set has its row from the last fetch done.
`ExecRow`	`getNextRowCore()`	Return the next row (if any) from the scan (if open).
`RowLocation`	`getRowLocation()`	This result set has its row location from the last fetch done.
`java.util.Properties`	`getScanProperties()`
`long`	`getTimeSpent(int type)`	Return the total amount of time spent in this ResultSet
`boolean`	`isForUpdate()`	Is this ResultSet or it's source result set for update
`void`	`openCore()`	open a scan on the table. scan parameters are evaluated at each open, so there is probably some way of altering their values...
`private java.lang.String`	`printPosition(int searchOperator, GeneratedMethod positionGetter, ExecIndexRow eiRow)`	Return a start or stop positioner as a String.
`java.lang.String`	`printStartPosition()`
`java.lang.String`	`printStopPosition()`
`void`	`reopenCore()`	reopen this ResultSet.
`boolean`	`requiresRelocking()`	Do we need to relock the row when going to the heap.
`private void`	`resetProbeVariables()`

Methods inherited from class org.apache.derby.impl.sql.execute.ScanResultSet
getScanIsolationLevel, initIsolationLevel, setRowLocationsState, toXML

Methods inherited from class org.apache.derby.impl.sql.execute.NoPutResultSetImpl
clearCurrentRow, clearOrderableCache, closeRowSource, getCursorName, getNextRowFromRowSource, getResultDescription, getValidColumns, 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, finish, getAbsoluteRow, getActivation, getAutoGeneratedKeysResultset, getBeginExecutionTimestamp, getCursorName, getEndExecutionTimestamp, getExecuteTime, getFirstRow, getLastRow, getNextRow, getPreviousRow, getRelativeRow, getResultDescription, getRowNumber, getSubqueryTrackingArray, getWarnings, isClosed, modifiedRowCount, open, returnsRows, setAfterLastRow, setBeforeFirstRow, toXML

Field Detail

hashtableBuilt
```
private boolean hashtableBuilt
```

startPosition
```
private ExecIndexRow startPosition
```

stopPosition
```
private ExecIndexRow stopPosition
```

compactRow
```
protected ExecRow compactRow
```

firstNext
```
protected boolean firstNext
```

numFetchedOnNext
```
private int numFetchedOnNext
```

entryVectorSize
```
private int entryVectorSize
```

entryVector
```
private java.util.List entryVector
```

conglomId
```
private long conglomId
```

scoci

protected StaticCompiledOpenConglomInfo scoci

startKeyGetter
```
private GeneratedMethod startKeyGetter
```

startSearchOperator
```
private int startSearchOperator
```

stopKeyGetter
```
private GeneratedMethod stopKeyGetter
```

stopSearchOperator
```
private int stopSearchOperator
```

scanQualifiers
```
public Qualifier[][] scanQualifiers
```

nextQualifiers
```
public Qualifier[][] nextQualifiers
```

initialCapacity
```
private int initialCapacity
```

loadFactor
```
private float loadFactor
```

maxCapacity
```
private int maxCapacity
```

userSuppliedOptimizerOverrides

public java.lang.String userSuppliedOptimizerOverrides

forUpdate
```
public boolean forUpdate
```

runTimeStatisticsOn
```
private boolean runTimeStatisticsOn
```

keyColumns
```
public int[] keyColumns
```

sameStartStopPosition
```
private boolean sameStartStopPosition
```

skipNullKeyColumns
```
private boolean skipNullKeyColumns
```

keepAfterCommit
```
private boolean keepAfterCommit
```

hashtable

protected BackingStoreHashtable hashtable

eliminateDuplicates
```
protected boolean eliminateDuplicates
```

scanProperties

public java.util.Properties scanProperties

startPositionString

public java.lang.String startPositionString

stopPositionString

public java.lang.String stopPositionString

hashtableSize
```
public int hashtableSize
```

isConstraint
```
public boolean isConstraint
```

DEFAULT_INITIAL_CAPACITY
```
public static final int DEFAULT_INITIAL_CAPACITY
```
See Also:

Constant Field Values

DEFAULT_LOADFACTOR
```
public static final float DEFAULT_LOADFACTOR
```
See Also:

Constant Field Values

DEFAULT_MAX_CAPACITY
```
public static final int DEFAULT_MAX_CAPACITY
```
See Also:

Constant Field Values

Constructor Detail

HashScanResultSet

HashScanResultSet(long conglomId,
                  StaticCompiledOpenConglomInfo scoci,
                  Activation activation,
                  int resultRowTemplate,
                  int resultSetNumber,
                  GeneratedMethod startKeyGetter,
                  int startSearchOperator,
                  GeneratedMethod stopKeyGetter,
                  int stopSearchOperator,
                  boolean sameStartStopPosition,
                  Qualifier[][] scanQualifiers,
                  Qualifier[][] nextQualifiers,
                  int initialCapacity,
                  float loadFactor,
                  int maxCapacity,
                  int hashKeyItem,
                  java.lang.String tableName,
                  java.lang.String userSuppliedOptimizerOverrides,
                  java.lang.String indexName,
                  boolean isConstraint,
                  boolean forUpdate,
                  int colRefItem,
                  int lockMode,
                  boolean tableLocked,
                  int isolationLevel,
                  boolean skipNullKeyColumns,
                  double optimizerEstimatedRowCount,
                  double optimizerEstimatedCost)
           throws StandardException

Throws:: StandardException

Method Detail
- canGetInstantaneousLocks
```
boolean canGetInstantaneousLocks()
```
  Can we get instantaneous locks when getting share row locks at READ COMMITTED.
  
  Specified by:
  
  canGetInstantaneousLocks in class ScanResultSet
- openCore
```
public void openCore()
              throws StandardException
```
  open a scan on the table. 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 failure to open
- reopenCore
```
public void reopenCore()
                throws StandardException
```
  reopen this ResultSet.
  
  Specified by:
  
  reopenCore in interface NoPutResultSet
  
  Overrides:
  
  reopenCore in class BasicNoPutResultSetImpl
  
  Throws:
  
  StandardException - thrown if cursor finished.
  
  See Also:
  
  NoPutResultSet.openCore()
- resetProbeVariables
```
private void resetProbeVariables()
                          throws StandardException
```
  Throws:
  
  StandardException
- getNextRowCore
```
public ExecRow getNextRowCore()
                       throws StandardException
```
  Return the next row (if any) from the scan (if open).
  
  Specified by:
  
  getNextRowCore in interface NoPutResultSet
  
  Specified by:
  
  getNextRowCore in class BasicNoPutResultSetImpl
  
  Returns:
  
  the next row in the result
  
  Throws:
  
  StandardException - thrown on failure to get next row
  
  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 ScanResultSet
  
  Throws:
  
  StandardException - thrown on error
- getTimeSpent
```
public long getTimeSpent(int type)
```
  Return the total amount of time spent in this ResultSet
  
  Specified by:
  
  getTimeSpent in interface 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).
- requiresRelocking
```
public boolean requiresRelocking()
```
  Description copied from interface: NoPutResultSet
  
  Do we need to relock the row when going to the heap.
  
  Specified by:
  
  requiresRelocking in interface NoPutResultSet
  
  Overrides:
  
  requiresRelocking in class BasicNoPutResultSetImpl
  
  Returns:
  
  Whether or not we need to relock the row when going to the heap.
  
  See Also:
  
  NoPutResultSet.requiresRelocking()
- getRowLocation
```
public RowLocation getRowLocation()
                           throws StandardException
```
  This result set has its row location from the last fetch done. If the cursor is closed, a null is returned.
  
  Specified by:
  
  getRowLocation in interface CursorResultSet
  
  Returns:
  
  the row location of the current cursor row.
  
  Throws:
  
  StandardException - thrown on failure to get row location
  
  See Also:
  
  CursorResultSet
- getCurrentRow
```
public ExecRow getCurrentRow()
                      throws StandardException
```
  This result set has its row from the last fetch done. If the cursor is closed, a null is returned.
  
  Specified by:
  
  getCurrentRow in interface CursorResultSet
  
  Returns:
  
  the last row returned;
  
  Throws:
  
  StandardException - thrown on failure.
  
  See Also:
  
  CursorResultSet
- printStartPosition
```
public java.lang.String printStartPosition()
```
- printStopPosition
```
public java.lang.String printStopPosition()
```
- printPosition
```
private java.lang.String printPosition(int searchOperator,
                                       GeneratedMethod positionGetter,
                                       ExecIndexRow eiRow)
```
  Return a start or stop positioner as a String.
- getScanProperties
```
public java.util.Properties getScanProperties()
```
- isForUpdate
```
public boolean isForUpdate()
```
  Is this ResultSet or it's source result set for update
  
  Specified by:
  
  isForUpdate in interface NoPutResultSet
  
  Overrides:
  
  isForUpdate in class NoPutResultSetImpl
  
  Returns:
  
  Whether or not the result set is for update.

Class HashScanResultSet

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.ScanResultSet

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

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 interface org.apache.derby.iapi.sql.ResultSet

Constructor Summary

Method Summary

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

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

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

Methods inherited from class java.lang.Object

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

Field Detail

hashtableBuilt

startPosition

stopPosition

compactRow

firstNext

numFetchedOnNext

entryVectorSize

entryVector

conglomId

scoci

startKeyGetter

startSearchOperator

stopKeyGetter

stopSearchOperator

scanQualifiers

nextQualifiers

initialCapacity

loadFactor

maxCapacity

userSuppliedOptimizerOverrides

forUpdate

runTimeStatisticsOn

keyColumns

sameStartStopPosition

skipNullKeyColumns

keepAfterCommit

hashtable

eliminateDuplicates

scanProperties

startPositionString

stopPositionString

hashtableSize

isConstraint

DEFAULT_INITIAL_CAPACITY

DEFAULT_LOADFACTOR

DEFAULT_MAX_CAPACITY

Constructor Detail

HashScanResultSet

Method Detail

canGetInstantaneousLocks

openCore

reopenCore

resetProbeVariables

getNextRowCore

close

getTimeSpent

requiresRelocking

getRowLocation

getCurrentRow

printStartPosition

printStopPosition

printPosition

getScanProperties

isForUpdate