org.apache.derby.impl.sql.execute

Class HashScanResultSet

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.

Field Summary

Fields

Modifier and Type	Field and 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
java.lang.String	indexName
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	tableName
java.lang.String	userSuppliedOptimizerOverrides

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

accessedCols, candidate, isolationLevel, lockMode, resultRowBuilder

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.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

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

Methods

Modifier and Type	Method and 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

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

clearCurrentRow, clearOrderableCache, closeRowSource, getCursorName, getNextRowFromRowSource, getResultDescription, getValidColumns, 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, finish, finishAndRTS, getAbsoluteRow, getActivation, getAutoGeneratedKeysResultset, getBeginExecutionTimestamp, getCompactRow, getCurrentTimeMillis, getElapsedMillis, getEndExecutionTimestamp, getEstimatedRowCount, getExecuteTime, getExecutionFactory, getFirstRow, getLanguageConnectionContext, getLastRow, getNextRow, getPointOfAttachment, getPreviousRow, getRelativeRow, getRowNumber, getSubqueryTrackingArray, getTransactionController, getWarnings, isClosed, isXplainOnlyMode, markAsTopResultSet, modifiedRowCount, open, recordConstructorTime, 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, finish, getAbsoluteRow, getActivation, getAutoGeneratedKeysResultset, getBeginExecutionTimestamp, getCursorName, getEndExecutionTimestamp, getExecuteTime, getFirstRow, getLastRow, getNextRow, getPreviousRow, getRelativeRow, getResultDescription, getRowNumber, getSubqueryTrackingArray, getWarnings, isClosed, modifiedRowCount, open, returnsRows, setAfterLastRow, setBeforeFirstRow

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

tableName

public java.lang.String tableName

userSuppliedOptimizerOverrides

public java.lang.String userSuppliedOptimizerOverrides

indexName

public java.lang.String indexName

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.