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

Modifier and Type	Field and Description
private boolean	allAscending
private boolean	alwaysSort
private ColumnOrdering[]	columnOrdering
private int	estimatedRowSize
private boolean	isTableValueCtorOrdering `true` if this instance orders a <table value constructor>.
private Object[]	resultRow
private int	resultSetNumber
private ResultSetNode	resultToSort
private SortCostController	scc
private boolean	sortNeeded

Access	Constructor and Description
pack-priv	OrderByList(ResultSetNode The result set this `OrderByList` is ordering. May be null rs, ContextManager The context manager cm) Constructor.

Method Summary

Modifier and Type	Method and Description
pack-priv void	addOrderByColumn(OrderByColumn The column to add to the list column) Add a column to the list
pack-priv boolean	Returns: Whether or not all columns in the list ascending. allAscending() Are all columns in the list ascending.
pack-priv void	bindOrderByColumns(ResultSetNode The underlying result set target) Bind the update columns by their names to the target resultset of the cursor specification.
pack-priv void	closeGap(int column which has been removed from the result column list gap) Adjust addedColumnOffset values due to removal of a duplicate column This routine is called by bind processing when it identifies and removes a column from the result column list which was pulled up due to its presence in the ORDER BY clause, but which was later found to be a duplicate.
public void	estimateCost(double The estimated number of rows to sort estimatedInputRows, RowOrdering The ordering of the input rows rowOrdering, CostEstimate A place to store the resulting cost resultCost) Implements org.apache.derby.iapi.sql.compile.RequiredRowOrdering.estimateCost. Estimate the cost of doing a sort for this row ordering, given the number of rows to be sorted.
pack-priv void	generate(ActivationClassBuilder the tool for building the class acb, MethodBuilder the method the generated code is to go into mb, ResultSetNode child) generate the sort result set operating over the source expression.
pack-priv OrderByColumn	getOrderByColumn(int The column to get from the list position) Get a column from the list
public int	getResultSetNumber()
public boolean	Returns: Whether or not a sort is needed. getSortNeeded() Implements org.apache.derby.iapi.sql.compile.RequiredRowOrdering.getSortNeeded. Get whether or not a sort is needed.
pack-priv boolean	Returns: Whether or not this order by list an in order prefix of the specified RCL. isInOrderPrefix(ResultColumnList The source RCL. sourceRCL) Is this order by list an in order prefix of the specified RCL.
public boolean	Returns: `true` if the `ORDER BY` is attached to a <table value constructor>, i.e. a `VALUES` clause. isTableValueCtorOrdering()
pack-priv void	pullUpOrderByColumns(ResultSetNode The underlying result set target) Pull up Order By columns by their names to the target resultset of the cursor specification.
pack-priv void	remapColumnReferencesToExpressions() Remap all ColumnReferences in this tree to be clones of the underlying expression.
pack-priv void	removeConstantColumns(PredicateList whereClause) Remove any constant columns from this order by list.
pack-priv void	removeDupColumns() Remove any duplicate columns from this order by list.
pack-priv ResultColumnList	reorderRCL(ResultColumnList The RCL to reorder. resultColumns) Build a new RCL with the same RCs as the passed in RCL but in an order that matches the ordering columns.
pack-priv boolean	requiresDescending(ColumnReference cRef, int numOptimizables) Determine whether or not this RequiredRowOrdering has a DESCENDING requirement for the column referenced by the received ColumnReference.
pack-priv void	resetToSourceRCs() Order by columns now point to the PRN above the node of interest.
public void	sortNeeded() Implements org.apache.derby.iapi.sql.compile.RequiredRowOrdering.sortNeeded. Indicate that a sort is necessary to fulfill this required ordering.
public void	sortNotNeeded() Implements org.apache.derby.iapi.sql.compile.RequiredRowOrdering.sortNotNeeded. Indicate that a sort is NOT necessary to fulfill this required ordering.
public int	sortRequired(RowOrdering The order of rows in question rowOrdering, OptimizableList The list of join participants optimizableList, int[] The current join order being considered by the optimizer. We need to look into this to determine if the outer optimizables are single row result set if the order by column is on an inner optimizable and that inner optimizable is not a one. `proposedJoinOrder` is a map onto `optimizableList`: it contains indexes of optimizables in that list in the join order proposed, cf. `OptimizerImpl#proposedJoinOrder`. proposedJoinOrder) Implements org.apache.derby.iapi.sql.compile.RequiredRowOrdering.sortRequired. Tell whether sorting is required for this RequiredRowOrdering, given a RowOrdering.
public int	sortRequired(RowOrdering The order of rows in the partial join order rowOrdering, JBitSet A bit map of the tables in the partial join order tableMap, OptimizableList The list of join participants optimizableList, int[] The current join order being considered by the optimizer. We need to look into this to determine if the outer optimizables are single row result set if the order by column is on an inner optimizable and that inner optimizable is not a one. `proposedJoinOrder` is a map onto `optimizableList`: it contains indexes of optimizables in that list in the join order proposed, cf. `OptimizerImpl#proposedJoinOrder`. DERBY-3926 and DERBY-6148 proposedJoinOrder) Implements org.apache.derby.iapi.sql.compile.RequiredRowOrdering.sortRequired. Tell whether sorting is required for this RequiredRowOrdering, given a RowOrdering representing a partial join order, and a bit map telling what tables are represented in the join order.
public String	toString() Overrides org.apache.derby.impl.sql.compile.QueryTreeNode.toString. Format this node as a string Each sub-class of QueryTreeNode should implement its own toString() method.

Inherited from org.apache.derby.impl.sql.compile.OrderedColumnList:: getColumnOrdering

allAscending	back to summary
private boolean allAscending

alwaysSort	back to summary
private boolean alwaysSort

columnOrdering	back to summary
private ColumnOrdering[] columnOrdering

estimatedRowSize	back to summary
private int estimatedRowSize

isTableValueCtorOrdering	back to summary
private boolean isTableValueCtorOrdering `true` if this instance orders a <table value constructor>. See `isTableValueCtorOrdering`.

resultRow	back to summary
private Object[] resultRow

resultSetNumber	back to summary
private int resultSetNumber

resultToSort	back to summary
private ResultSetNode resultToSort

scc	back to summary
private SortCostController scc

sortNeeded	back to summary
private boolean sortNeeded

OrderByList	back to summary
pack-priv OrderByList(ResultSetNode rs, ContextManager cm) Constructor. Initialize with the type of the result set this `OrderByList` is attached to, e.g. `SELECT`, `VALUES` or a set operation. Parameters rs:ResultSetNode The result set this `OrderByList` is ordering. May be null cm:ContextManager The context manager

Method Detail

addOrderByColumn	back to summary
pack-priv void addOrderByColumn(OrderByColumn column) Add a column to the list Parameters column:OrderByColumn The column to add to the list

addOrderByColumn

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pack-priv void addOrderByColumn(OrderByColumn column)

Add a column to the list

Parameters

column:OrderByColumn: The column to add to the list

allAscending	back to summary
pack-priv boolean allAscending() Are all columns in the list ascending. Returns:boolean Whether or not all columns in the list ascending.

allAscending

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pack-priv boolean allAscending()

Are all columns in the list ascending.

Returns:boolean: Whether or not all columns in the list ascending.

bindOrderByColumns	back to summary
pack-priv void bindOrderByColumns(ResultSetNode target) throws StandardException Bind the update columns by their names to the target resultset of the cursor specification. Parameters target:ResultSetNode The underlying result set Exceptions StandardException: Thrown on error

bindOrderByColumns

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pack-priv void bindOrderByColumns(ResultSetNode target) throws StandardException

Bind the update columns by their names to the target resultset of the cursor specification.

Parameters

target:ResultSetNode: The underlying result set

Exceptions

StandardException:: Thrown on error

closeGap	back to summary
pack-priv void closeGap(int gap) Adjust addedColumnOffset values due to removal of a duplicate column This routine is called by bind processing when it identifies and removes a column from the result column list which was pulled up due to its presence in the ORDER BY clause, but which was later found to be a duplicate. The OrderByColumn instance for the removed column has been adjusted to point to the true column in the result column list and its addedColumnOffset has been reset to -1. This routine finds any other OrderByColumn instances which had an offset greater than that of the column that has been deleted, and decrements their addedColumOffset to account for the deleted column's removal. Parameters gap:int column which has been removed from the result column list

closeGap

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pack-priv void closeGap(int gap)

Adjust addedColumnOffset values due to removal of a duplicate column This routine is called by bind processing when it identifies and removes a column from the result column list which was pulled up due to its presence in the ORDER BY clause, but which was later found to be a duplicate. The OrderByColumn instance for the removed column has been adjusted to point to the true column in the result column list and its addedColumnOffset has been reset to -1. This routine finds any other OrderByColumn instances which had an offset greater than that of the column that has been deleted, and decrements their addedColumOffset to account for the deleted column's removal.

Parameters

gap:int: column which has been removed from the result column list

estimateCost back to summary

estimateCost	back to summary
public void estimateCost(double estimatedInputRows, RowOrdering rowOrdering, CostEstimate resultCost) throws StandardException Implements org.apache.derby.iapi.sql.compile.RequiredRowOrdering.estimateCost. Doc from org.apache.derby.iapi.sql.compile.RequiredRowOrdering.estimateCost. Estimate the cost of doing a sort for this row ordering, given the number of rows to be sorted. This does not take into account whether the sort is really needed. It also estimates the number of result rows. Parameters estimatedInputRows:double The estimated number of rows to sort rowOrdering:RowOrdering The ordering of the input rows resultCost:CostEstimate A place to store the resulting cost Exceptions StandardException: Thrown on error See Also `RequiredRowOrdering#estimateCost`

public void estimateCost(double estimatedInputRows, RowOrdering rowOrdering, CostEstimate resultCost) throws StandardException

Implements org.apache.derby.iapi.sql.compile.RequiredRowOrdering.estimateCost.

Doc from org.apache.derby.iapi.sql.compile.RequiredRowOrdering.estimateCost.

Estimate the cost of doing a sort for this row ordering, given the number of rows to be sorted. This does not take into account whether the sort is really needed. It also estimates the number of result rows.

Parameters

estimatedInputRows:double: The estimated number of rows to sort
rowOrdering:RowOrdering: The ordering of the input rows
resultCost:CostEstimate: A place to store the resulting cost

Exceptions

StandardException:: Thrown on error

See Also

RequiredRowOrdering#estimateCost

generate	back to summary
pack-priv void generate(ActivationClassBuilder acb, MethodBuilder mb, ResultSetNode child) throws StandardException generate the sort result set operating over the source expression. Parameters acb:ActivationClassBuilder the tool for building the class mb:MethodBuilder the method the generated code is to go into Exceptions StandardException: thrown on failure

generate

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pack-priv void generate(ActivationClassBuilder acb, MethodBuilder mb, ResultSetNode child) throws StandardException

generate the sort result set operating over the source expression.

Parameters

acb:ActivationClassBuilder: the tool for building the class
mb:MethodBuilder: the method the generated code is to go into

Exceptions

StandardException:: thrown on failure

getOrderByColumn	back to summary
pack-priv OrderByColumn getOrderByColumn(int position) Get a column from the list Parameters position:int The column to get from the list

getOrderByColumn

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pack-priv OrderByColumn getOrderByColumn(int position)

Get a column from the list

Parameters

position:int: The column to get from the list

getResultSetNumber	back to summary
public int getResultSetNumber()

getSortNeeded	back to summary
public boolean getSortNeeded() Implements org.apache.derby.iapi.sql.compile.RequiredRowOrdering.getSortNeeded. Get whether or not a sort is needed. Returns:boolean Whether or not a sort is needed.

getSortNeeded

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public boolean getSortNeeded()

Implements org.apache.derby.iapi.sql.compile.RequiredRowOrdering.getSortNeeded.

Get whether or not a sort is needed.

Returns:boolean: Whether or not a sort is needed.

isInOrderPrefix	back to summary
pack-priv boolean isInOrderPrefix(ResultColumnList sourceRCL) Is this order by list an in order prefix of the specified RCL. This is useful when deciding if an order by list can be eliminated due to a sort from an underlying distinct or union. Parameters sourceRCL:ResultColumnList The source RCL. Returns:boolean Whether or not this order by list an in order prefix of the specified RCL.

isInOrderPrefix

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pack-priv boolean isInOrderPrefix(ResultColumnList sourceRCL)

Is this order by list an in order prefix of the specified RCL. This is useful when deciding if an order by list can be eliminated due to a sort from an underlying distinct or union.

Parameters

sourceRCL:ResultColumnList: The source RCL.

Returns:boolean

Whether or not this order by list an in order prefix of the specified RCL.

isTableValueCtorOrdering	back to summary
public boolean isTableValueCtorOrdering() Returns:boolean `true` if the `ORDER BY` is attached to a <table value constructor>, i.e. a `VALUES` clause.

pullUpOrderByColumns	back to summary
pack-priv void pullUpOrderByColumns(ResultSetNode target) throws StandardException Pull up Order By columns by their names to the target resultset of the cursor specification. Parameters target:ResultSetNode The underlying result set

pullUpOrderByColumns

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pack-priv void pullUpOrderByColumns(ResultSetNode target) throws StandardException

Pull up Order By columns by their names to the target resultset of the cursor specification.

Parameters

target:ResultSetNode: The underlying result set

remapColumnReferencesToExpressions	back to summary
pack-priv void remapColumnReferencesToExpressions() throws StandardException Remap all ColumnReferences in this tree to be clones of the underlying expression. Exceptions StandardException: Thrown on error

remapColumnReferencesToExpressions

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pack-priv void remapColumnReferencesToExpressions() throws StandardException

Remap all ColumnReferences in this tree to be clones of the underlying expression.

Exceptions

StandardException:: Thrown on error

removeConstantColumns	back to summary
pack-priv void removeConstantColumns(PredicateList whereClause) Remove any constant columns from this order by list. Constant columns are ones where all of the column references are equal to constant expressions according to the given predicate list.

removeDupColumns	back to summary
pack-priv void removeDupColumns() Remove any duplicate columns from this order by list. For example, one may "ORDER BY 1, 1, 2" can be reduced to "ORDER BY 1, 2". Beetle 5401.

reorderRCL	back to summary
pack-priv ResultColumnList reorderRCL(ResultColumnList resultColumns) throws StandardException Build a new RCL with the same RCs as the passed in RCL but in an order that matches the ordering columns. Parameters resultColumns:ResultColumnList The RCL to reorder. Exceptions StandardException: Thrown on error

reorderRCL

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pack-priv ResultColumnList reorderRCL(ResultColumnList resultColumns) throws StandardException

Build a new RCL with the same RCs as the passed in RCL but in an order that matches the ordering columns.

Parameters

resultColumns:ResultColumnList: The RCL to reorder.

Exceptions

StandardException:: Thrown on error

requiresDescending	back to summary
pack-priv boolean requiresDescending(ColumnReference cRef, int numOptimizables) throws StandardException Determine whether or not this RequiredRowOrdering has a DESCENDING requirement for the column referenced by the received ColumnReference.

resetToSourceRCs	back to summary
pack-priv void resetToSourceRCs() Order by columns now point to the PRN above the node of interest. We need them to point to the RCL under that one. This is useful when combining sorts where we need to reorder the sorting columns.

sortNeeded back to summary

sortNeeded	back to summary
public void sortNeeded() Implements org.apache.derby.iapi.sql.compile.RequiredRowOrdering.sortNeeded. Doc from org.apache.derby.iapi.sql.compile.RequiredRowOrdering.sortNeeded. Indicate that a sort is necessary to fulfill this required ordering. This method may be called many times during a single optimization. See Also `RequiredRowOrdering#sortNeeded`

public void sortNeeded()

Implements org.apache.derby.iapi.sql.compile.RequiredRowOrdering.sortNeeded.

Doc from org.apache.derby.iapi.sql.compile.RequiredRowOrdering.sortNeeded.

Indicate that a sort is necessary to fulfill this required ordering. This method may be called many times during a single optimization.

See Also: RequiredRowOrdering#sortNeeded

sortNotNeeded back to summary

sortNotNeeded	back to summary
public void sortNotNeeded() Implements org.apache.derby.iapi.sql.compile.RequiredRowOrdering.sortNotNeeded. Doc from org.apache.derby.iapi.sql.compile.RequiredRowOrdering.sortNotNeeded. Indicate that a sort is NOT necessary to fulfill this required ordering. This method may be called many times during a single optimization. See Also `RequiredRowOrdering#sortNotNeeded`

public void sortNotNeeded()

Implements org.apache.derby.iapi.sql.compile.RequiredRowOrdering.sortNotNeeded.

Doc from org.apache.derby.iapi.sql.compile.RequiredRowOrdering.sortNotNeeded.

Indicate that a sort is *NOT* necessary to fulfill this required ordering. This method may be called many times during a single optimization.

See Also: RequiredRowOrdering#sortNotNeeded

sortRequired back to summary

sortRequired	back to summary
public int sortRequired(RowOrdering rowOrdering, OptimizableList optimizableList, int[] proposedJoinOrder) throws StandardException Implements org.apache.derby.iapi.sql.compile.RequiredRowOrdering.sortRequired. Doc from org.apache.derby.iapi.sql.compile.RequiredRowOrdering.sortRequired. Tell whether sorting is required for this RequiredRowOrdering, given a RowOrdering. Parameters rowOrdering:RowOrdering The order of rows in question optimizableList:OptimizableList The list of join participants proposedJoinOrder:int[] The current join order being considered by the optimizer. We need to look into this to determine if the outer optimizables are single row result set if the order by column is on an inner optimizable and that inner optimizable is not a one. `proposedJoinOrder` is a map onto `optimizableList`: it contains indexes of optimizables in that list in the join order proposed, cf. `OptimizerImpl#proposedJoinOrder`. Returns:int SORT_REQUIRED if sorting is required, ELIMINATE_DUPS if no sorting is required but duplicates must be eliminated (i.e. the rows are in the right order but there may be duplicates), NOTHING_REQUIRED is no operation is required Exceptions StandardException: Thrown on error See Also `RequiredRowOrdering#sortRequired(RowOrdering, OptimizableList, int[])`

public int sortRequired(RowOrdering rowOrdering, OptimizableList optimizableList, int[] proposedJoinOrder) throws StandardException

Implements org.apache.derby.iapi.sql.compile.RequiredRowOrdering.sortRequired.

Doc from org.apache.derby.iapi.sql.compile.RequiredRowOrdering.sortRequired.

Tell whether sorting is required for this RequiredRowOrdering, given a RowOrdering.

Parameters

rowOrdering:RowOrdering: The order of rows in question
optimizableList:OptimizableList: The list of join participants
proposedJoinOrder:int[]: The current join order being considered by the optimizer. We need to look into this to determine if the outer optimizables are single row result set if the order by column is on an inner optimizable and that inner optimizable is not a one. proposedJoinOrder is a map onto optimizableList: it contains indexes of optimizables in that list in the join order proposed, cf. OptimizerImpl#proposedJoinOrder.

Returns:int

SORT_REQUIRED if sorting is required, ELIMINATE_DUPS if no sorting is required but duplicates must be eliminated (i.e. the rows are in the right order but there may be duplicates), NOTHING_REQUIRED is no operation is required

Exceptions

StandardException:: Thrown on error

sortRequired back to summary

sortRequired	back to summary
public int sortRequired(RowOrdering rowOrdering, JBitSet tableMap, OptimizableList optimizableList, int[] proposedJoinOrder) throws StandardException Implements org.apache.derby.iapi.sql.compile.RequiredRowOrdering.sortRequired. Doc from org.apache.derby.iapi.sql.compile.RequiredRowOrdering.sortRequired. Tell whether sorting is required for this RequiredRowOrdering, given a RowOrdering representing a partial join order, and a bit map telling what tables are represented in the join order. This is useful for reducing the number of cases the optimizer has to consider. Parameters rowOrdering:RowOrdering The order of rows in the partial join order tableMap:JBitSet A bit map of the tables in the partial join order optimizableList:OptimizableList The list of join participants proposedJoinOrder:int[] The current join order being considered by the optimizer. We need to look into this to determine if the outer optimizables are single row result set if the order by column is on an inner optimizable and that inner optimizable is not a one. `proposedJoinOrder` is a map onto `optimizableList`: it contains indexes of optimizables in that list in the join order proposed, cf. `OptimizerImpl#proposedJoinOrder`. DERBY-3926 and DERBY-6148 Returns:int SORT_REQUIRED if sorting is required, ELIMINATE_DUPS if no sorting is required by duplicates must be eliminated (i.e. the rows are in the right order but there may be duplicates), NOTHING_REQUIRED is no operation is required Exceptions StandardException: Thrown on error See Also `RequiredRowOrdering#sortRequired(RowOrdering, JBitSet, OptimizableList, int[])`

public int sortRequired(RowOrdering rowOrdering, JBitSet tableMap, OptimizableList optimizableList, int[] proposedJoinOrder) throws StandardException

Implements org.apache.derby.iapi.sql.compile.RequiredRowOrdering.sortRequired.

Doc from org.apache.derby.iapi.sql.compile.RequiredRowOrdering.sortRequired.

Tell whether sorting is required for this RequiredRowOrdering, given a RowOrdering representing a partial join order, and a bit map telling what tables are represented in the join order. This is useful for reducing the number of cases the optimizer has to consider.

Parameters

rowOrdering:RowOrdering: The order of rows in the partial join order
tableMap:JBitSet: A bit map of the tables in the partial join order
optimizableList:OptimizableList: The list of join participants
proposedJoinOrder:int[]: The current join order being considered by the optimizer. We need to look into this to determine if the outer optimizables are single row result set if the order by column is on an inner optimizable and that inner optimizable is not a one. proposedJoinOrder is a map onto optimizableList: it contains indexes of optimizables in that list in the join order proposed, cf. OptimizerImpl#proposedJoinOrder. DERBY-3926 and DERBY-6148

Returns:int

SORT_REQUIRED if sorting is required, ELIMINATE_DUPS if no sorting is required by duplicates must be eliminated (i.e. the rows are in the right order but there may be duplicates), NOTHING_REQUIRED is no operation is required

Exceptions

StandardException:: Thrown on error

toString	back to summary
public String toString() Overrides org.apache.derby.impl.sql.compile.QueryTreeNode.toString. Doc from org.apache.derby.impl.sql.compile.QueryTreeNode.toString. Format this node as a string Each sub-class of QueryTreeNode should implement its own toString() method. In each case, toString() should format the class members that are not sub-types of QueryTreeNode (printSubNodes() takes care of following the references to sub-nodes, and toString() takes care of all members that are not sub-nodes). Newlines should be used liberally - one good way to do this is to have a newline at the end of each formatted member. It's also a good idea to put the name of each member in front of the formatted value. For example, the code might look like: "memberName: " + memberName + "\n" + ... Vector members containing subclasses of QueryTreeNode should subclass QueryTreeNodeVector. Such subclasses form a special case: These classes should not implement printSubNodes, since there is generic handling in QueryTreeNodeVector. They should only implement toString if they contain additional members. Returns:String This node formatted as a String Annotations @Override

toString

back to summary

public String toString()

Overrides org.apache.derby.impl.sql.compile.QueryTreeNode.toString.

Doc from org.apache.derby.impl.sql.compile.QueryTreeNode.toString.

Format this node as a string Each sub-class of QueryTreeNode should implement its own toString() method. In each case, toString() should format the class members that are not sub-types of QueryTreeNode (printSubNodes() takes care of following the references to sub-nodes, and toString() takes care of all members that are not sub-nodes). Newlines should be used liberally - one good way to do this is to have a newline at the end of each formatted member. It's also a good idea to put the name of each member in front of the formatted value. For example, the code might look like: "memberName: " + memberName + "\n" + ... Vector members containing subclasses of QueryTreeNode should subclass QueryTreeNodeVector. Such subclasses form a special case: These classes should not implement printSubNodes, since there is generic handling in QueryTreeNodeVector. They should only implement toString if they contain additional members.

Returns:String

This node formatted as a String

Annotations

@Override

pack-priv Class OrderByList

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Field Detail

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