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

Method Summary

Modifier and Type	Method and Description
public void	addOptPredicate(OptimizablePredicate The predicate to add optPredicate) Add the given OptimizablePredicate to the end of this list.
public void	adjustForSortElimination(RequiredRowOrdering ordering) Walk through the predicates in this list and make any adjustments that are required to allow for proper handling of an ORDER BY clause.
public void	classify(Optimizable The Optimizable table for which to classify the predicates in this list. optTable, ConglomerateDescriptor The ConglomerateDescriptor for which to classify the predicates in this list. cd) Classify the predicates in this list according to the given table and conglomerate.
public void	copyPredicatesToOtherList(OptimizablePredicateList The predicateList to xfer to otherList) Non-destructive copy of all of the predicates from this list to the other list.
public void	generateQualifiers(ExpressionClassBuilderInterface The ExpressionClassBuilderInterface for the class we are building acb, MethodBuilder The method the generated code is going into mb, Optimizable The Optimizable table the Qualifiers are on optTable, boolean Generate absolute column positions if true, else relative column positions (within the underlying row) absolute) Generate the qualifiers for a scan.
public void	generateStartKey(ExpressionClassBuilderInterface The ExpressionClassBuilderInterface for the class we're building acb, MethodBuilder The method the generated code is to go into mb, Optimizable The Optimizable table the start key is for optTable) Generate the start key for a heap or index scan.
public void	generateStopKey(ExpressionClassBuilderInterface The ExpressionClassBuilderInterface for the class we're building acb, MethodBuilder the method the generated code is to go into mb, Optimizable The Optimizable table the stop key is for optTable) Generate the stop key for a heap or index scan.
public OptimizablePredicate	Returns: OptimizablePredicate The nth OptimizablePredicate in the list. getOptPredicate(int "index" (0 based) into the list. n) Return the nth OptimizablePredicate in the list.
public int	Returns: the position of the predicate in the list which corresponds to the equijoin. If no quijoin predicate found, then the return value will be -1 hasEqualityPredicateOnOrderedColumn(Optimizable optTable, int columnNumber, boolean isNullOkay) Check into the predicate list if the passed column has an equijoin predicate on it.
public boolean	Returns: Whether or not there is an optimizable equality predicate on the specified column. hasOptimizableEqualityPredicate(Optimizable The optimizable the column comes from. optTable, int The column number within the base table. columnNumber, boolean boolean, whether or not the IS NULL operator satisfies the search isNullOkay) Is there an optimizable equality predicate on the specified column?
public boolean	Returns: Whether or not there is an optimizable equijoin on the specified column. hasOptimizableEquijoin(Optimizable The optimizable the column comes from. optTable, int The column number within the base table. columnNumber) Is there an optimizable equijoin on the specified column?
public boolean	Returns: Whether or not the specified entry in the list is a redundant predicate. isRedundantPredicate(int The entry in the list predNum) Return whether or not the specified entry in the list is a redundant predicate.
public void	markAllPredicatesQualifiers() Mark all of the predicates as Qualifiers and set the numberOfQualifiers to reflect this.
public void	pushUsefulPredicates(Optimizable An Optimizable for the table in question optTable) Determine which predicates in this list are useful for limiting the scan on the given table using its best conglomerate.
public void	putOptimizableEqualityPredicateFirst(Optimizable The optimizable the column comes from. optTable, int The column number within the base table. columnNumber) Find the optimizable equality predicate on the specified column and make it the first predicate in this list.
public void	removeOptPredicate(int The index. predCtr) Remove the OptimizablePredicate at the specified index (0-based) from the list.
public boolean	Returns: Whether or not we can use the same key for both the start and stop key. sameStartStopPosition() Can we use the same key for both the start and stop key.
public double	selectivity(Optimizable the Optimizable that the predicate list restricts. optTable) calculate the selectivity for a set of predicates.
public void	setPredicatesAndProperties(OptimizablePredicateList The list to set the same as this one. otherList) Sets the given list to have the same elements as this one, and the same properties as this one (number of qualifiers and start and stop predicates.
public int	Returns: integer The number of OptimizablePredicates in the list. size() Return the number of OptimizablePredicates in the list.
public int	startOperator(Optimizable optTable) Get the start operator for the given Optimizable for a heap or index scan.
public int	stopOperator(Optimizable optTable) Get the stop operator for the given Optimizable for a heap or index scan.
public void	transferAllPredicates(OptimizablePredicateList otherList) Transfer all the predicates from this list to the given list.
public void	transferPredicates(OptimizablePredicateList The predicateList to xfer to otherList, JBitSet The table map to check against referencedTableMap, Optimizable The table to order the new predicates against table) Transfer the predicates whose referenced set is contained by the specified referencedTableMap from this list to the other list.
public boolean	Returns: true if this predicate list can limit the scan useful(Optimizable An Optimizable for the table in question optTable, ConglomerateDescriptor A ConglomerateDescriptor for the conglomerate in question cd) Return true if this predicate list is useful for limiting the scan on the given table using the given conglomerate.

Method Detail

addOptPredicate	back to summary
public void addOptPredicate(OptimizablePredicate optPredicate) Add the given OptimizablePredicate to the end of this list. Parameters optPredicate:OptimizablePredicate The predicate to add

addOptPredicate

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public void addOptPredicate(OptimizablePredicate optPredicate)

Add the given OptimizablePredicate to the end of this list.

Parameters

optPredicate:OptimizablePredicate: The predicate to add

adjustForSortElimination	back to summary
public void adjustForSortElimination(RequiredRowOrdering ordering) throws StandardException Walk through the predicates in this list and make any adjustments that are required to allow for proper handling of an ORDER BY clause.

classify	back to summary
public void classify(Optimizable optTable, ConglomerateDescriptor cd) throws StandardException Classify the predicates in this list according to the given table and conglomerate. Each predicate can be a start key, stop key, and/or qualifier, or it can be none of the above. This method also orders the predicates to match the order of the columns in a keyed conglomerate. No ordering is done for heaps. Parameters optTable:Optimizable The Optimizable table for which to classify the predicates in this list. cd:ConglomerateDescriptor The ConglomerateDescriptor for which to classify the predicates in this list. Exceptions StandardException: Thrown on error

classify

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public void classify(Optimizable optTable, ConglomerateDescriptor cd) throws StandardException

Classify the predicates in this list according to the given table and conglomerate. Each predicate can be a start key, stop key, and/or qualifier, or it can be none of the above. This method also orders the predicates to match the order of the columns in a keyed conglomerate. No ordering is done for heaps.

Parameters

optTable:Optimizable: The Optimizable table for which to classify the predicates in this list.
cd:ConglomerateDescriptor: The ConglomerateDescriptor for which to classify the predicates in this list.

Exceptions

StandardException:: Thrown on error

copyPredicatesToOtherList	back to summary
public void copyPredicatesToOtherList(OptimizablePredicateList otherList) throws StandardException Non-destructive copy of all of the predicates from this list to the other list. This is useful when splitting out a set of predicates from a larger set, like when generating a HashScanResultSet. Parameters otherList:OptimizablePredicateList The predicateList to xfer to Exceptions StandardException: Thrown on error

copyPredicatesToOtherList

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public void copyPredicatesToOtherList(OptimizablePredicateList otherList) throws StandardException

Non-destructive copy of all of the predicates from this list to the other list. This is useful when splitting out a set of predicates from a larger set, like when generating a HashScanResultSet.

Parameters

otherList:OptimizablePredicateList: The predicateList to xfer to

Exceptions

StandardException:: Thrown on error

generateQualifiers	back to summary
public void generateQualifiers(ExpressionClassBuilderInterface acb, MethodBuilder mb, Optimizable optTable, boolean absolute) throws StandardException Generate the qualifiers for a scan. This method generates an array of Qualifiers, and fills them in with calls to the factory method for generating Qualifiers in the constructor for the activation. It stores the array of Qualifiers in a field in the activation, and returns a reference to that field. If there are no qualifiers, it initializes the array of Qualifiers to null. Parameters acb:ExpressionClassBuilderInterface The ExpressionClassBuilderInterface for the class we are building mb:MethodBuilder The method the generated code is going into optTable:Optimizable The Optimizable table the Qualifiers are on absolute:boolean Generate absolute column positions if true, else relative column positions (within the underlying row) Exceptions StandardException: Thrown on error

generateQualifiers

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public void generateQualifiers(ExpressionClassBuilderInterface acb, MethodBuilder mb, Optimizable optTable, boolean absolute) throws StandardException

Generate the qualifiers for a scan. This method generates an array of Qualifiers, and fills them in with calls to the factory method for generating Qualifiers in the constructor for the activation. It stores the array of Qualifiers in a field in the activation, and returns a reference to that field. If there are no qualifiers, it initializes the array of Qualifiers to null.

Parameters

acb:ExpressionClassBuilderInterface: The ExpressionClassBuilderInterface for the class we are building
mb:MethodBuilder: The method the generated code is going into
optTable:Optimizable: The Optimizable table the Qualifiers are on
absolute:boolean: Generate absolute column positions if true, else relative column positions (within the underlying row)

Exceptions

StandardException:: Thrown on error

generateStartKey	back to summary
public void generateStartKey(ExpressionClassBuilderInterface acb, MethodBuilder mb, Optimizable optTable) throws StandardException Generate the start key for a heap or index scan. Parameters acb:ExpressionClassBuilderInterface The ExpressionClassBuilderInterface for the class we're building mb:MethodBuilder The method the generated code is to go into optTable:Optimizable The Optimizable table the start key is for Exceptions StandardException: Thrown on error

generateStartKey

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public void generateStartKey(ExpressionClassBuilderInterface acb, MethodBuilder mb, Optimizable optTable) throws StandardException

Generate the start key for a heap or index scan.

Parameters

acb:ExpressionClassBuilderInterface: The ExpressionClassBuilderInterface for the class we're building
mb:MethodBuilder: The method the generated code is to go into
optTable:Optimizable: The Optimizable table the start key is for

Exceptions

StandardException:: Thrown on error

generateStopKey	back to summary
public void generateStopKey(ExpressionClassBuilderInterface acb, MethodBuilder mb, Optimizable optTable) throws StandardException Generate the stop key for a heap or index scan. Parameters acb:ExpressionClassBuilderInterface The ExpressionClassBuilderInterface for the class we're building mb:MethodBuilder the method the generated code is to go into optTable:Optimizable The Optimizable table the stop key is for Exceptions StandardException: Thrown on error

generateStopKey

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public void generateStopKey(ExpressionClassBuilderInterface acb, MethodBuilder mb, Optimizable optTable) throws StandardException

Generate the stop key for a heap or index scan.

Parameters

acb:ExpressionClassBuilderInterface: The ExpressionClassBuilderInterface for the class we're building
mb:MethodBuilder: the method the generated code is to go into
optTable:Optimizable: The Optimizable table the stop key is for

Exceptions

StandardException:: Thrown on error

getOptPredicate	back to summary
public OptimizablePredicate getOptPredicate(int n) Return the nth OptimizablePredicate in the list. Parameters n:int "index" (0 based) into the list. Returns:OptimizablePredicate OptimizablePredicate The nth OptimizablePredicate in the list.

getOptPredicate

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public OptimizablePredicate getOptPredicate(int n)

Return the nth OptimizablePredicate in the list.

Parameters

n:int: "index" (0 based) into the list.

Returns:OptimizablePredicate

OptimizablePredicate The nth OptimizablePredicate in the list.

hasEqualityPredicateOnOrderedColumn	back to summary
public int hasEqualityPredicateOnOrderedColumn(Optimizable optTable, int columnNumber, boolean isNullOkay) throws StandardException Check into the predicate list if the passed column has an equijoin predicate on it. Returns:int the position of the predicate in the list which corresponds to the equijoin. If no quijoin predicate found, then the return value will be -1

hasEqualityPredicateOnOrderedColumn

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public int hasEqualityPredicateOnOrderedColumn(Optimizable optTable, int columnNumber, boolean isNullOkay) throws StandardException

Check into the predicate list if the passed column has an equijoin predicate on it.

Returns:int: the position of the predicate in the list which corresponds to the equijoin. If no quijoin predicate found, then the return value will be -1

hasOptimizableEqualityPredicate	back to summary
public boolean hasOptimizableEqualityPredicate(Optimizable optTable, int columnNumber, boolean isNullOkay) throws StandardException Is there an optimizable equality predicate on the specified column? Parameters optTable:Optimizable The optimizable the column comes from. columnNumber:int The column number within the base table. isNullOkay:boolean boolean, whether or not the IS NULL operator satisfies the search Returns:boolean Whether or not there is an optimizable equality predicate on the specified column. Exceptions StandardException: Thrown on error

hasOptimizableEqualityPredicate

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public boolean hasOptimizableEqualityPredicate(Optimizable optTable, int columnNumber, boolean isNullOkay) throws StandardException

Is there an optimizable equality predicate on the specified column?

Parameters

optTable:Optimizable: The optimizable the column comes from.
columnNumber:int: The column number within the base table.
isNullOkay:boolean: boolean, whether or not the IS NULL operator satisfies the search

Returns:boolean

Whether or not there is an optimizable equality predicate on the specified column.

Exceptions

StandardException:: Thrown on error

hasOptimizableEquijoin	back to summary
public boolean hasOptimizableEquijoin(Optimizable optTable, int columnNumber) throws StandardException Is there an optimizable equijoin on the specified column? Parameters optTable:Optimizable The optimizable the column comes from. columnNumber:int The column number within the base table. Returns:boolean Whether or not there is an optimizable equijoin on the specified column. Exceptions StandardException: Thrown on error

hasOptimizableEquijoin

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public boolean hasOptimizableEquijoin(Optimizable optTable, int columnNumber) throws StandardException

Is there an optimizable equijoin on the specified column?

Parameters

optTable:Optimizable: The optimizable the column comes from.
columnNumber:int: The column number within the base table.

Returns:boolean

Whether or not there is an optimizable equijoin on the specified column.

Exceptions

StandardException:: Thrown on error

isRedundantPredicate	back to summary
public boolean isRedundantPredicate(int predNum) Return whether or not the specified entry in the list is a redundant predicate. This is useful for selectivity calculations because we do not want redundant predicates included in the selectivity calculation. Parameters predNum:int The entry in the list Returns:boolean Whether or not the specified entry in the list is a redundant predicate.

isRedundantPredicate

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public boolean isRedundantPredicate(int predNum)

Return whether or not the specified entry in the list is a redundant predicate. This is useful for selectivity calculations because we do not want redundant predicates included in the selectivity calculation.

Parameters

predNum:int: The entry in the list

Returns:boolean

Whether or not the specified entry in the list is a redundant predicate.

markAllPredicatesQualifiers	back to summary
public void markAllPredicatesQualifiers() Mark all of the predicates as Qualifiers and set the numberOfQualifiers to reflect this. This is useful for hash joins where all of the predicates in the list to be evaluated during the probe into the hash table on a next are qualifiers.

pushUsefulPredicates	back to summary
public void pushUsefulPredicates(Optimizable optTable) throws StandardException Determine which predicates in this list are useful for limiting the scan on the given table using its best conglomerate. Remove those predicates from this list and push them down to the given Optimizable table. The predicates are pushed down in the order of the index columns that they qualify. Also, the predicates are "marked" as start predicates, stop predicates, or qualifier predicates. Finally, the start and stop operators are set in the given Optimizable. Parameters optTable:Optimizable An Optimizable for the table in question Exceptions StandardException: Thrown on error

pushUsefulPredicates

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public void pushUsefulPredicates(Optimizable optTable) throws StandardException

Determine which predicates in this list are useful for limiting the scan on the given table using its best conglomerate. Remove those predicates from this list and push them down to the given Optimizable table. The predicates are pushed down in the order of the index columns that they qualify. Also, the predicates are "marked" as start predicates, stop predicates, or qualifier predicates. Finally, the start and stop operators are set in the given Optimizable.

Parameters

optTable:Optimizable: An Optimizable for the table in question

Exceptions

StandardException:: Thrown on error

putOptimizableEqualityPredicateFirst	back to summary
public void putOptimizableEqualityPredicateFirst(Optimizable optTable, int columnNumber) throws StandardException Find the optimizable equality predicate on the specified column and make it the first predicate in this list. This is useful for hash joins where Qualifier[0] is assumed to be on the hash key. Parameters optTable:Optimizable The optimizable the column comes from. columnNumber:int The column number within the base table. Exceptions StandardException: Thrown on error

putOptimizableEqualityPredicateFirst

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public void putOptimizableEqualityPredicateFirst(Optimizable optTable, int columnNumber) throws StandardException

Find the optimizable equality predicate on the specified column and make it the first predicate in this list. This is useful for hash joins where Qualifier[0] is assumed to be on the hash key.

Parameters

optTable:Optimizable: The optimizable the column comes from.
columnNumber:int: The column number within the base table.

Exceptions

StandardException:: Thrown on error

removeOptPredicate	back to summary
public void removeOptPredicate(int predCtr) throws StandardException Remove the OptimizablePredicate at the specified index (0-based) from the list. Parameters predCtr:int The index. Exceptions StandardException: Thrown on error

removeOptPredicate

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public void removeOptPredicate(int predCtr) throws StandardException

Remove the OptimizablePredicate at the specified index (0-based) from the list.

Parameters

predCtr:int: The index.

Exceptions

StandardException:: Thrown on error

sameStartStopPosition	back to summary
public boolean sameStartStopPosition() throws StandardException Can we use the same key for both the start and stop key. This is possible when doing an exact match on an index where there are no other sargable predicates. Returns:boolean Whether or not we can use the same key for both the start and stop key. Exceptions StandardException: Thrown on error

sameStartStopPosition

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public boolean sameStartStopPosition() throws StandardException

Can we use the same key for both the start and stop key. This is possible when doing an exact match on an index where there are no other sargable predicates.

Returns:boolean

Whether or not we can use the same key for both the start and stop key.

Exceptions

StandardException:: Thrown on error

selectivity	back to summary
public double selectivity(Optimizable optTable) throws StandardException calculate the selectivity for a set of predicates. If statistics exist for the predicates this method uses the statistics. If statistics do not exist, then simply call selectivity for each of the predicates and return the result. Parameters optTable:Optimizable the Optimizable that the predicate list restricts.

selectivity

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public double selectivity(Optimizable optTable) throws StandardException

calculate the selectivity for a set of predicates. If statistics exist for the predicates this method uses the statistics. If statistics do not exist, then simply call selectivity for each of the predicates and return the result.

Parameters

optTable:Optimizable: the Optimizable that the predicate list restricts.

setPredicatesAndProperties	back to summary
public void setPredicatesAndProperties(OptimizablePredicateList otherList) throws StandardException Sets the given list to have the same elements as this one, and the same properties as this one (number of qualifiers and start and stop predicates. Parameters otherList:OptimizablePredicateList The list to set the same as this one. Exceptions StandardException: Thrown on error

setPredicatesAndProperties

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public void setPredicatesAndProperties(OptimizablePredicateList otherList) throws StandardException

Sets the given list to have the same elements as this one, and the same properties as this one (number of qualifiers and start and stop predicates.

Parameters

otherList:OptimizablePredicateList: The list to set the same as this one.

Exceptions

StandardException:: Thrown on error

size	back to summary
public int size() Return the number of OptimizablePredicates in the list. Returns:int integer The number of OptimizablePredicates in the list.

size

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public int size()

Return the number of OptimizablePredicates in the list.

Returns:int: integer The number of OptimizablePredicates in the list.

startOperator	back to summary
public int startOperator(Optimizable optTable) Get the start operator for the given Optimizable for a heap or index scan.

stopOperator	back to summary
public int stopOperator(Optimizable optTable) Get the stop operator for the given Optimizable for a heap or index scan.

transferAllPredicates	back to summary
public void transferAllPredicates(OptimizablePredicateList otherList) throws StandardException Transfer all the predicates from this list to the given list. Exceptions StandardException: Thrown on error

transferAllPredicates

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public void transferAllPredicates(OptimizablePredicateList otherList) throws StandardException

Transfer all the predicates from this list to the given list.

Exceptions

StandardException:: Thrown on error

transferPredicates	back to summary
public void transferPredicates(OptimizablePredicateList otherList, JBitSet referencedTableMap, Optimizable table) throws StandardException Transfer the predicates whose referenced set is contained by the specified referencedTableMap from this list to the other list. This is useful when splitting out a set of predicates from a larger set, like when generating a HashScanResultSet. Parameters otherList:OptimizablePredicateList The predicateList to xfer to referencedTableMap:JBitSet The table map to check against table:Optimizable The table to order the new predicates against Exceptions StandardException: Thrown on error

transferPredicates

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public void transferPredicates(OptimizablePredicateList otherList, JBitSet referencedTableMap, Optimizable table) throws StandardException

Transfer the predicates whose referenced set is contained by the specified referencedTableMap from this list to the other list. This is useful when splitting out a set of predicates from a larger set, like when generating a HashScanResultSet.

Parameters

otherList:OptimizablePredicateList: The predicateList to xfer to
referencedTableMap:JBitSet: The table map to check against
table:Optimizable: The table to order the new predicates against

Exceptions

StandardException:: Thrown on error

useful	back to summary
public boolean useful(Optimizable optTable, ConglomerateDescriptor cd) throws StandardException Return true if this predicate list is useful for limiting the scan on the given table using the given conglomerate. Parameters optTable:Optimizable An Optimizable for the table in question cd:ConglomerateDescriptor A ConglomerateDescriptor for the conglomerate in question Returns:boolean true if this predicate list can limit the scan Exceptions StandardException: Thrown on error

useful

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public boolean useful(Optimizable optTable, ConglomerateDescriptor cd) throws StandardException

Return true if this predicate list is useful for limiting the scan on the given table using the given conglomerate.

Parameters

optTable:Optimizable: An Optimizable for the table in question
cd:ConglomerateDescriptor: A ConglomerateDescriptor for the conglomerate in question

Returns:boolean

true if this predicate list can limit the scan

Exceptions

StandardException:: Thrown on error

public Interface OptimizablePredicateList

Method Summary

Method Detail