Apache Derby Database Engine and Embedded JDBC Driver 10.17.1.0 · org.apache.derby.impl.sql.execute.TableScanResultSet

Modifier and Type	Field and Description
public boolean	coarserLock
protected long	conglomId
protected boolean	currentRowIsValid
protected DynamicCompiledOpenConglomInfo	dcoci
private long	estimatedRowCount
protected boolean	firstScan
public boolean	forUpdate
protected int[]	indexCols
public boolean	isConstraint
protected boolean	isKeyed
protected boolean	nextDone
public boolean	oneRowScan
protected BackingStoreHashtable	past2FutureTbl This field is used by beetle 3865, updateable cursor using index.
public Qualifier[][]	qualifiers
protected boolean	qualify
private RowLocation	rlTemplate
public int	rowsPerRead
protected long	rowsThisScan
protected boolean	runTimeStatisticsOn
pack-priv final boolean	sameStartStopPosition
protected ScanController	scanController
protected boolean	scanControllerOpened
private Properties	scanProperties
protected boolean	scanRepositioned
protected StaticCompiledOpenConglomInfo	scoci
protected GeneratedMethod	startKeyGetter
protected ExecIndexRow	startPosition
public String	startPositionString
protected int	startSearchOperator
protected GeneratedMethod	stopKeyGetter
protected ExecIndexRow	stopPosition
public String	stopPositionString
protected int	stopSearchOperator
public String	userSuppliedOptimizerOverrides

Access	Constructor and Description
pack-priv	TableScanResultSet(long conglomId, StaticCompiledOpenConglomInfo scoci, Activation activation, int resultRowTemplate, int resultSetNumber, GeneratedMethod startKeyGetter, int startSearchOperator, GeneratedMethod stopKeyGetter, int stopSearchOperator, boolean sameStartStopPosition, Qualifier[][] qualifiers, String tableName, String userSuppliedOptimizerOverrides, String indexName, boolean isConstraint, boolean forUpdate, int colRefItem, int indexColItem, int lockMode, boolean tableLocked, int isolationLevel, int rowsPerRead, boolean oneRowScan, double optimizerEstimatedRowCount, double optimizerEstimatedCost)

Method Summary

Modifier and Type	Method and Description
protected boolean	canGetInstantaneousLocks() Implements abstract org.apache.derby.impl.sql.execute.ScanResultSet.canGetInstantaneousLocks. Can we get instantaneous locks when getting share row locks at READ COMMITTED.
public Object	clone() Overrides java.lang.Object.clone. Shallow clone this result set.
public void	close() Overrides org.apache.derby.impl.sql.execute.ScanResultSet.close. Implements org.apache.derby.iapi.sql.ResultSet.close. If the result set has been opened, close the open scan.
public ExecRow	Returns: the last row returned; getCurrentRow() Implements org.apache.derby.iapi.sql.execute.CursorResultSet.getCurrentRow. This result set has its row from the last fetch done.
public ExecRow	getNextRowCore() Implements abstract org.apache.derby.impl.sql.execute.BasicNoPutResultSetImpl.getNextRowCore. Implements org.apache.derby.iapi.sql.execute.NoPutResultSet.getNextRowCore. Return the next row (if any) from the scan (if open).
public RowLocation	Returns: the row location of the current cursor row. getRowLocation() Implements org.apache.derby.iapi.sql.execute.CursorResultSet.getRowLocation. This result set has its row location from the last fetch done.
public Properties	getScanProperties()
public long	Returns: long The total amount of time spent (in milliseconds). getTimeSpent(int CURRENT_RESULTSET_ONLY - time spent only in this ResultSet ENTIRE_RESULTSET_TREE - time spent in this ResultSet and below. type) Implements org.apache.derby.iapi.sql.ResultSet.getTimeSpent. Return the total amount of time spent in this ResultSet
pack-priv void	initStartAndStopKey() Initialize the `startPosition` and `stopPosition` fields which are used to limit the rows returned by the scan.
public boolean	Returns: Whether or not the result set is for update. isForUpdate() Overrides org.apache.derby.impl.sql.execute.NoPutResultSetImpl.isForUpdate. Implements org.apache.derby.iapi.sql.execute.NoPutResultSet.isForUpdate. Is this ResultSet or it's source result set for update
pack-priv boolean	loopControl(boolean moreRows)
public void	openCore() Implements org.apache.derby.iapi.sql.execute.NoPutResultSet.openCore. open a scan on the table.
protected void	openScanController(TransactionController tc)
public void	positionScanAtRowLocation(RowLocation row location of the current cursor row rl) Overrides org.apache.derby.impl.sql.execute.NoPutResultSetImpl.positionScanAtRowLocation. Implements org.apache.derby.iapi.sql.execute.NoPutResultSet.positionScanAtRowLocation. Positions the cursor in the specified rowLocation.
private String	printPosition(int searchOperator, GeneratedMethod positionGetter, ExecIndexRow positioner) Return a start or stop positioner as a String.
public String	printStartPosition() Print an array of Qualifiers to the trace stream.
public String	printStopPosition()
public void	reopenCore() Overrides org.apache.derby.impl.sql.execute.BasicNoPutResultSetImpl.reopenCore. Implements org.apache.derby.iapi.sql.execute.NoPutResultSet.reopenCore. Reopen a table scan.
protected void	reopenScanController()
public boolean	requiresRelocking() Overrides org.apache.derby.impl.sql.execute.BasicNoPutResultSetImpl.requiresRelocking. Implements org.apache.derby.iapi.sql.execute.NoPutResultSet.requiresRelocking. Do we need to relock the row when going to the heap.
protected final void	setRowCountIfPossible(long The number of rows to update the scanController to rowsThisScan) Update the number of rows in the scan controller.

Inherited from org.apache.derby.impl.sql.execute.ScanResultSet:: getScanIsolationLevel initIsolationLevel setRowLocationsState toXML

Field Detail

coarserLock	back to summary
public boolean coarserLock

conglomId	back to summary
protected long conglomId

currentRowIsValid	back to summary
protected boolean currentRowIsValid

dcoci	back to summary
protected DynamicCompiledOpenConglomInfo dcoci

estimatedRowCount	back to summary
private long estimatedRowCount

firstScan	back to summary
protected boolean firstScan

forUpdate	back to summary
public boolean forUpdate

indexCols	back to summary
protected int[] indexCols

isConstraint	back to summary
public boolean isConstraint

isKeyed	back to summary
protected boolean isKeyed

nextDone	back to summary
protected boolean nextDone

oneRowScan	back to summary
public boolean oneRowScan

past2FutureTbl	back to summary
protected BackingStoreHashtable past2FutureTbl This field is used by beetle 3865, updateable cursor using index. It is a hash table containing updated rows that are thrown into future direction of the index scan, and as a result we'll hit it again but should skip it. The hash table will spill to disk if it grows too big to be kept in memory.

qualifiers	back to summary
public Qualifier[][] qualifiers

qualify	back to summary
protected boolean qualify

rlTemplate	back to summary
private RowLocation rlTemplate

rowsPerRead	back to summary
public int rowsPerRead

rowsThisScan	back to summary
protected long rowsThisScan

runTimeStatisticsOn	back to summary
protected boolean runTimeStatisticsOn

sameStartStopPosition	back to summary
pack-priv final boolean sameStartStopPosition

scanController	back to summary
protected ScanController scanController

scanControllerOpened	back to summary
protected boolean scanControllerOpened

scanProperties	back to summary
private Properties scanProperties

scanRepositioned	back to summary
protected boolean scanRepositioned

scoci	back to summary
protected StaticCompiledOpenConglomInfo scoci

startKeyGetter	back to summary
protected GeneratedMethod startKeyGetter

startPosition	back to summary
protected ExecIndexRow startPosition

startPositionString	back to summary
public String startPositionString

startSearchOperator	back to summary
protected int startSearchOperator

stopKeyGetter	back to summary
protected GeneratedMethod stopKeyGetter

stopPosition	back to summary
protected ExecIndexRow stopPosition

stopPositionString	back to summary
public String stopPositionString

stopSearchOperator	back to summary
protected int stopSearchOperator

userSuppliedOptimizerOverrides	back to summary
public String userSuppliedOptimizerOverrides

Constructor Detail

TableScanResultSet	back to summary
pack-priv TableScanResultSet(long conglomId, StaticCompiledOpenConglomInfo scoci, Activation activation, int resultRowTemplate, int resultSetNumber, GeneratedMethod startKeyGetter, int startSearchOperator, GeneratedMethod stopKeyGetter, int stopSearchOperator, boolean sameStartStopPosition, Qualifier[][] qualifiers, String tableName, String userSuppliedOptimizerOverrides, String indexName, boolean isConstraint, boolean forUpdate, int colRefItem, int indexColItem, int lockMode, boolean tableLocked, int isolationLevel, int rowsPerRead, boolean oneRowScan, double optimizerEstimatedRowCount, double optimizerEstimatedCost) throws StandardException

TableScanResultSet

back to summary

pack-priv TableScanResultSet(long conglomId, StaticCompiledOpenConglomInfo scoci, Activation activation, int resultRowTemplate, int resultSetNumber, GeneratedMethod startKeyGetter, int startSearchOperator, GeneratedMethod stopKeyGetter, int stopSearchOperator, boolean sameStartStopPosition, Qualifier[][] qualifiers, String tableName, String userSuppliedOptimizerOverrides, String indexName, boolean isConstraint, boolean forUpdate, int colRefItem, int indexColItem, int lockMode, boolean tableLocked, int isolationLevel, int rowsPerRead, boolean oneRowScan, double optimizerEstimatedRowCount, double optimizerEstimatedCost) throws StandardException

Method Detail

canGetInstantaneousLocks	back to summary
protected boolean canGetInstantaneousLocks() Implements abstract org.apache.derby.impl.sql.execute.ScanResultSet.canGetInstantaneousLocks. Can we get instantaneous locks when getting share row locks at READ COMMITTED.

canGetInstantaneousLocks

back to summary

protected boolean canGetInstantaneousLocks()

Implements abstract org.apache.derby.impl.sql.execute.ScanResultSet.canGetInstantaneousLocks.

Can we get instantaneous locks when getting share row locks at READ COMMITTED.

clone	back to summary
public Object clone() Overrides java.lang.Object.clone. Shallow clone this result set. Used in trigger reference. beetle 4373. Returns:Object Doc from java.lang.Object.clone. a clone of this instance.

clone

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public Object clone()

Overrides java.lang.Object.clone.

Shallow clone this result set. Used in trigger reference. beetle 4373.

Returns:Object

Doc from java.lang.Object.clone.

a clone of this instance.

close	back to summary
public void close() throws StandardException Overrides org.apache.derby.impl.sql.execute.ScanResultSet.close. Implements org.apache.derby.iapi.sql.ResultSet.close. If the result set has been opened, close the open scan. Exceptions StandardException: on error

back to summary

public void close() throws StandardException

Overrides org.apache.derby.impl.sql.execute.ScanResultSet.close.

Implements org.apache.derby.iapi.sql.ResultSet.close.

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

Exceptions

StandardException:: on error

getCurrentRow back to summary

getCurrentRow	back to summary
public ExecRow getCurrentRow() throws StandardException Implements org.apache.derby.iapi.sql.execute.CursorResultSet.getCurrentRow. This result set has its row from the last fetch done. If the cursor is closed, the row has been deleted, or no longer qualifies (for forward only result sets) a null is returned. Returns:ExecRow the last row returned; Exceptions StandardException: thrown on failure. See Also `CursorResultSet`

public ExecRow getCurrentRow() throws StandardException

Implements org.apache.derby.iapi.sql.execute.CursorResultSet.getCurrentRow.

This result set has its row from the last fetch done. If the cursor is closed, the row has been deleted, or no longer qualifies (for forward only result sets) a null is returned.

Returns:ExecRow

the last row returned;

Exceptions

StandardException:: thrown on failure.

See Also

CursorResultSet

getNextRowCore	back to summary
public ExecRow getNextRowCore() throws StandardException Implements abstract org.apache.derby.impl.sql.execute.BasicNoPutResultSetImpl.getNextRowCore. Implements org.apache.derby.iapi.sql.execute.NoPutResultSet.getNextRowCore. Return the next row (if any) from the scan (if open). Returns:ExecRow Doc from org.apache.derby.iapi.sql.execute.NoPutResultSet.getNextRowCore. the next row in the result Exceptions StandardException: thrown on failure to get next row

getNextRowCore

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public ExecRow getNextRowCore() throws StandardException

Implements abstract org.apache.derby.impl.sql.execute.BasicNoPutResultSetImpl.getNextRowCore.

Implements org.apache.derby.iapi.sql.execute.NoPutResultSet.getNextRowCore.

Return the next row (if any) from the scan (if open).

Returns:ExecRow

Doc from org.apache.derby.iapi.sql.execute.NoPutResultSet.getNextRowCore.

the next row in the result

Exceptions

StandardException:: thrown on failure to get next row

getRowLocation back to summary

getRowLocation	back to summary
public RowLocation getRowLocation() throws StandardException Implements org.apache.derby.iapi.sql.execute.CursorResultSet.getRowLocation. This result set has its row location from the last fetch done. If the cursor is closed, or the row has been deleted a null is returned. Returns:RowLocation the row location of the current cursor row. Exceptions StandardException: thrown on failure to get row location See Also `CursorResultSet`

public RowLocation getRowLocation() throws StandardException

Implements org.apache.derby.iapi.sql.execute.CursorResultSet.getRowLocation.

This result set has its row location from the last fetch done. If the cursor is closed, or the row has been deleted a null is returned.

Returns:RowLocation

the row location of the current cursor row.

Exceptions

StandardException:: thrown on failure to get row location

See Also

CursorResultSet

getScanProperties	back to summary
public Properties getScanProperties()

getTimeSpent	back to summary
public long getTimeSpent(int type) Implements org.apache.derby.iapi.sql.ResultSet.getTimeSpent. Return the total amount of time spent in this ResultSet Parameters type:int CURRENT_RESULTSET_ONLY - time spent only in this ResultSet ENTIRE_RESULTSET_TREE - time spent in this ResultSet and below. Returns:long long The total amount of time spent (in milliseconds).

getTimeSpent

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public long getTimeSpent(int type)

Implements org.apache.derby.iapi.sql.ResultSet.getTimeSpent.

Return the total amount of time spent in this ResultSet

Parameters

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

Returns:long

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

initStartAndStopKey	back to summary
pack-priv void initStartAndStopKey() throws StandardException Initialize the `startPosition` and `stopPosition` fields which are used to limit the rows returned by the scan.

isForUpdate	back to summary
public boolean isForUpdate() Overrides org.apache.derby.impl.sql.execute.NoPutResultSetImpl.isForUpdate. Implements org.apache.derby.iapi.sql.execute.NoPutResultSet.isForUpdate. Is this ResultSet or it's source result set for update Returns:boolean Whether or not the result set is for update.

isForUpdate

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public boolean isForUpdate()

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

Implements org.apache.derby.iapi.sql.execute.NoPutResultSet.isForUpdate.

Is this ResultSet or it's source result set for update

Returns:boolean: Whether or not the result set is for update.

loopControl	back to summary
pack-priv boolean loopControl(boolean moreRows) throws StandardException

openCore	back to summary
public void openCore() throws StandardException Implements org.apache.derby.iapi.sql.execute.NoPutResultSet.openCore. open a scan on the table. scan parameters are evaluated at each open, so there is probably some way of altering their values... Exceptions StandardException: thrown on failure to open

openCore

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public void openCore() throws StandardException

Implements org.apache.derby.iapi.sql.execute.NoPutResultSet.openCore.

open a scan on the table. scan parameters are evaluated at each open, so there is probably some way of altering their values...

Exceptions

StandardException:: thrown on failure to open

openScanController	back to summary
protected void openScanController(TransactionController tc) throws StandardException

positionScanAtRowLocation back to summary

public void positionScanAtRowLocation(RowLocation rl) throws StandardException

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

Implements org.apache.derby.iapi.sql.execute.NoPutResultSet.positionScanAtRowLocation.

Doc from org.apache.derby.iapi.sql.execute.NoPutResultSet.positionScanAtRowLocation.

Positions the cursor in the specified rowLocation. Used for scrollable insensitive result sets in order to position the cursor back to a row that has already be visited.

Parameters

rl:RowLocation: row location of the current cursor row

Exceptions

StandardException:: thrown on failure to get location from storage engine

printPosition	back to summary
private String printPosition(int searchOperator, GeneratedMethod positionGetter, ExecIndexRow positioner) Return a start or stop positioner as a String. If we already generated the information, then use that. Otherwise, invoke the activation to get it.

printStartPosition	back to summary
public String printStartPosition() Print an array of Qualifiers to the trace stream.

printStopPosition	back to summary
public String printStopPosition()

reopenCore

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public void reopenCore() throws StandardException

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

Implements org.apache.derby.iapi.sql.execute.NoPutResultSet.reopenCore.

Reopen a table scan. Here we take advantage of the reopenScan() interface on scanController for optimimal performance on joins where we are an inner table.

Exceptions

StandardException:: thrown on failure to open

reopenScanController	back to summary
protected void reopenScanController() throws StandardException

requiresRelocking back to summary

public boolean requiresRelocking()

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

Implements org.apache.derby.iapi.sql.execute.NoPutResultSet.requiresRelocking.

Doc from org.apache.derby.iapi.sql.execute.NoPutResultSet.requiresRelocking.

Do we need to relock the row when going to the heap.

Returns:boolean: Whether or not we need to relock the row when going to the heap.
See Also: NoPutResultSet#requiresRelocking

setRowCountIfPossible

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protected final void setRowCountIfPossible(long rowsThisScan) throws StandardException

Update the number of rows in the scan controller.

Note

It would be more efficient to only update the scan controller if the optimizer's estimated number of rows were wrong by more than some threshold (like 10%). This would require a little more work than I have the time for now, however, as the row estimate that is given to this result set is the total number of rows for all scans, not the number of rows per scan.

Parameters

rowsThisScan:long: The number of rows to update the scanController to

Exceptions

StandardException:: Thrown on error

pack-priv Class TableScanResultSet

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail