Apache Derby Database Engine and Embedded JDBC Driver 10.17.1.0 · org.apache.derby.impl.store.access.sort.MergeSort

Field Summary

Modifier and Type	Field and Description
protected boolean	alreadyInOrder Whether the rows are expected to be in order on insert, as passed in on create.
protected ColumnOrdering[]	columnOrdering The column ordering as passed in on create.
protected boolean[]	columnOrderingAscendingMap A lookup table to speed up lookup of Ascending state of a column,
protected int[]	columnOrderingMap A lookup table to speed up lookup of a column associated with the i'th column to compare.
protected boolean[]	columnOrderingNullsLowMap A lookup table to speed up lookup of nulls-low ordering of a column,
private MergeInserter	inserter The inserter that's being used to insert rows into the sort.
private Vector<Long>	mergeRuns A vector of merge runs, produced by the MergeInserter.
pack-priv static Properties	properties Properties for mergeSort
private Scan	scan The scan that's being used to return rows from the sort.
private SortBuffer	sortBuffer An ordered set of the leftover rows that didn't go in the last merge run (might be all the rows if there are no merge runs).
pack-priv int	sortBufferMax The maximum number of entries a sort buffer can hold.
pack-priv int	sortBufferMin The minimum number of entries a sort buffer can hold.
pack-priv SortObserver	sortObserver The sort observer.
private int	state Maintains the current state of the sort as defined in the preceding values.
private static final int	STATE_CLOSED
private static final int	STATE_DONE_INSERTING
private static final int	STATE_DONE_SCANNING
private static final int	STATE_INITIALIZED
private static final int	STATE_INSERTING
private static final int	STATE_SCANNING
protected DataValueDescriptor[]	template The template as passed in on create.

Constructor Summary

Access	Constructor and Description
pack-priv	MergeSort()

Method Summary

Modifier and Type	Method and Description
private boolean	Returns: `true` if the ordering is valid, `false` if not. checkColumnOrdering(DataValueDescriptor[] template, ColumnOrdering[] columnOrdering) Check the column ordering against the template, making sure that each column is present in the template, is not mentioned more than once, and that the columns isn't `null`.
pack-priv void	checkColumnTypes(DataValueDescriptor[] row) Check that the columns in the row agree with the columns in the template, both in number and in type.
protected int	compare(DataValueDescriptor[] r1, DataValueDescriptor[] r2)
pack-priv long	createMergeRun(TransactionManager tran, SortBuffer sortBuffer) Remove all the rows from the sort buffer and store them in a temporary conglomerate.
pack-priv void	doneInserting(MergeInserter inserter, SortBuffer sortBuffer, Vector<Long> mergeRuns) An inserter is closing.
pack-priv void	doneScanning(Scan scan, SortBuffer sortBuffer)
pack-priv void	doneScanning(Scan scan, SortBuffer sortBuffer, Vector<Long> mergeRuns)
public void	drop(TransactionController tran) Implements org.apache.derby.iapi.store.access.conglomerate.Sort.drop. Drop the sort.
pack-priv void	dropMergeRuns(TransactionManager tran) Get rid of the merge runs, if there are any.
public void	initialize(DataValueDescriptor[] template, ColumnOrdering[] columnOrdering, SortObserver sortObserver, boolean alreadyInOrder, long estimatedRows, int sortBufferMax) Go from the CLOSED to the INITIALIZED state.
private void	multiStageMerge(TransactionManager tran)
public SortController	open(TransactionManager tran) Implements org.apache.derby.iapi.store.access.conglomerate.Sort.open. Open a sort controller.
public ScanControllerRowSource	openSortRowSource(TransactionManager tran) Implements org.apache.derby.iapi.store.access.conglomerate.Sort.openSortRowSource. Open a row source to get rows out of the sorter.
public ScanManager	openSortScan(TransactionManager tran, boolean hold) Implements org.apache.derby.iapi.store.access.conglomerate.Sort.openSortScan. Open a scan controller.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

alreadyInOrder	back to summary
protected boolean alreadyInOrder Whether the rows are expected to be in order on insert, as passed in on create.

columnOrdering	back to summary
protected ColumnOrdering[] columnOrdering The column ordering as passed in on create. Valid when the state is INITIALIZED through SCANNING, null otherwise. May be null if there is no column ordering - this means that all rows are considered to be duplicates, and the sort will only emit a single row.

columnOrderingAscendingMap	back to summary
protected boolean[] columnOrderingAscendingMap A lookup table to speed up lookup of Ascending state of a column,

columnOrderingMap	back to summary
protected int[] columnOrderingMap A lookup table to speed up lookup of a column associated with the i'th column to compare. To find the column id to compare as the i'th column look in columnOrderingMap[i].

columnOrderingNullsLowMap	back to summary
protected boolean[] columnOrderingNullsLowMap A lookup table to speed up lookup of nulls-low ordering of a column,

inserter	back to summary
private MergeInserter inserter The inserter that's being used to insert rows into the sort. This field is only valid when the state is INSERTING.

mergeRuns	back to summary
private Vector<Long> mergeRuns A vector of merge runs, produced by the MergeInserter. Might be null if no merge runs were produced. It is a vector of container ids.

properties	back to summary
pack-priv static Properties properties Properties for mergeSort

scan	back to summary
private Scan scan The scan that's being used to return rows from the sort. This field is only valid when the state is SCANNING.

sortBuffer	back to summary
private SortBuffer sortBuffer An ordered set of the leftover rows that didn't go in the last merge run (might be all the rows if there are no merge runs).

sortBufferMax	back to summary
pack-priv int sortBufferMax The maximum number of entries a sort buffer can hold.

sortBufferMin	back to summary
pack-priv int sortBufferMin The minimum number of entries a sort buffer can hold.

sortObserver	back to summary
pack-priv SortObserver sortObserver The sort observer. May be null. Used as a callback.

state	back to summary
private int state Maintains the current state of the sort as defined in the preceding values. Sorts start off and end up closed.

STATE_CLOSED	back to summary
private static final int STATE_CLOSED

STATE_DONE_INSERTING	back to summary
private static final int STATE_DONE_INSERTING

STATE_DONE_SCANNING	back to summary
private static final int STATE_DONE_SCANNING

STATE_INITIALIZED	back to summary
private static final int STATE_INITIALIZED

STATE_INSERTING	back to summary
private static final int STATE_INSERTING

STATE_SCANNING	back to summary
private static final int STATE_SCANNING

template	back to summary
protected DataValueDescriptor[] template The template as passed in on create. Valid when the state is INITIALIZED through SCANNING, null otherwise.

Constructor Detail

MergeSort	back to summary
pack-priv MergeSort()

Method Detail

checkColumnOrdering back to summary

checkColumnOrdering	back to summary
private boolean checkColumnOrdering(DataValueDescriptor[] template, ColumnOrdering[] columnOrdering) Check the column ordering against the template, making sure that each column is present in the template, is not mentioned more than once, and that the columns isn't `null`. Intended to be called as part of a sanity check. All columns are orderable, since `DataValueDescriptor` extends `Orderable`. Returns:boolean `true` if the ordering is valid, `false` if not.

private boolean checkColumnOrdering(DataValueDescriptor[] template, ColumnOrdering[] columnOrdering)

Check the column ordering against the template, making sure that each column is present in the template, is not mentioned more than once, and that the columns isn't null.

Intended to be called as part of a sanity check. All columns are orderable, since DataValueDescriptor extends Orderable.

Returns:boolean: true if the ordering is valid, false if not.

checkColumnTypes	back to summary
pack-priv void checkColumnTypes(DataValueDescriptor[] row) throws StandardException Check that the columns in the row agree with the columns in the template, both in number and in type. XXX (nat) Currently checks that the classes implementing each column are the same -- is this right?

checkColumnTypes

back to summary

pack-priv void checkColumnTypes(DataValueDescriptor[] row) throws StandardException

Check that the columns in the row agree with the columns in the template, both in number and in type.

XXX (nat) Currently checks that the classes implementing each column are the same -- is this right?

compare	back to summary
protected int compare(DataValueDescriptor[] r1, DataValueDescriptor[] r2) throws StandardException

createMergeRun	back to summary
pack-priv long createMergeRun(TransactionManager tran, SortBuffer sortBuffer) throws StandardException Remove all the rows from the sort buffer and store them in a temporary conglomerate. The temporary conglomerate is a "merge run". Returns the container id of the merge run.

doneInserting	back to summary
pack-priv void doneInserting(MergeInserter inserter, SortBuffer sortBuffer, Vector<Long> mergeRuns) An inserter is closing.

doneScanning	back to summary
pack-priv void doneScanning(Scan scan, SortBuffer sortBuffer)

doneScanning	back to summary
pack-priv void doneScanning(Scan scan, SortBuffer sortBuffer, Vector<Long> mergeRuns)

drop back to summary

drop	back to summary
public void drop(TransactionController tran) throws StandardException Implements org.apache.derby.iapi.store.access.conglomerate.Sort.drop. Drop the sort. See Also `Sort#drop`

public void drop(TransactionController tran) throws StandardException

Implements org.apache.derby.iapi.store.access.conglomerate.Sort.drop.

Drop the sort.

See Also: Sort#drop

dropMergeRuns	back to summary
pack-priv void dropMergeRuns(TransactionManager tran) Get rid of the merge runs, if there are any. Must not cause any errors because it's called during error processing.

initialize	back to summary
public void initialize(DataValueDescriptor[] template, ColumnOrdering[] columnOrdering, SortObserver sortObserver, boolean alreadyInOrder, long estimatedRows, int sortBufferMax) throws StandardException Go from the CLOSED to the INITIALIZED state.

multiStageMerge	back to summary
private void multiStageMerge(TransactionManager tran) throws StandardException

open back to summary

open	back to summary
public SortController open(TransactionManager tran) throws StandardException Implements org.apache.derby.iapi.store.access.conglomerate.Sort.open. Open a sort controller. This implementation only supports a single sort controller per sort. Exceptions StandardException: Doc from org.apache.derby.iapi.store.access.conglomerate.Sort.open. Standard exception policy. See Also `Sort#open`

public SortController open(TransactionManager tran) throws StandardException

Implements org.apache.derby.iapi.store.access.conglomerate.Sort.open.

Open a sort controller.

This implementation only supports a single sort controller per sort.

Exceptions

StandardException:

Doc from org.apache.derby.iapi.store.access.conglomerate.Sort.open.

Standard exception policy.

See Also

Sort#open

openSortRowSource back to summary

openSortRowSource	back to summary
public ScanControllerRowSource openSortRowSource(TransactionManager tran) throws StandardException Implements org.apache.derby.iapi.store.access.conglomerate.Sort.openSortRowSource. Open a row source to get rows out of the sorter. Exceptions StandardException: Doc from org.apache.derby.iapi.store.access.conglomerate.Sort.openSortRowSource. Standard exception policy. See Also `Sort#openSortRowSource`

public ScanControllerRowSource openSortRowSource(TransactionManager tran) throws StandardException

Implements org.apache.derby.iapi.store.access.conglomerate.Sort.openSortRowSource.

Open a row source to get rows out of the sorter.

Exceptions

StandardException:

Doc from org.apache.derby.iapi.store.access.conglomerate.Sort.openSortRowSource.

Standard exception policy.

See Also

Sort#openSortRowSource

openSortScan back to summary

openSortScan	back to summary
public ScanManager openSortScan(TransactionManager tran, boolean hold) throws StandardException Implements org.apache.derby.iapi.store.access.conglomerate.Sort.openSortScan. Open a scan controller. Exceptions StandardException: Doc from org.apache.derby.iapi.store.access.conglomerate.Sort.openSortScan. Standard exception policy. See Also `Sort#openSortScan`

public ScanManager openSortScan(TransactionManager tran, boolean hold) throws StandardException

Implements org.apache.derby.iapi.store.access.conglomerate.Sort.openSortScan.

Open a scan controller.

Exceptions

StandardException:

Doc from org.apache.derby.iapi.store.access.conglomerate.Sort.openSortScan.

Standard exception policy.

See Also

Sort#openSortScan

pack-priv Class MergeSort

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail