Class UniqueWithDuplicateNullsIndexSortObserver
- java.lang.Object
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- org.apache.derby.impl.sql.execute.BasicSortObserver
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- org.apache.derby.impl.sql.execute.UniqueWithDuplicateNullsIndexSortObserver
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- All Implemented Interfaces:
SortObserver
public class UniqueWithDuplicateNullsIndexSortObserver extends BasicSortObserver
UniqueWithDuplicateNullsIndexSortObserver is implementation of BasicSortObserver for eliminating non null duplicates from the backing index of unique constraint. This class is implemented to check for special case of distinct sorting where duplicate keys are allowed only if there is a null in the key part.
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Field Summary
Fields Modifier and Type Field Description private UUID
constraintId
private boolean
deferrable
private boolean
deferred
private BackingStoreHashtable
deferredDuplicates
private java.lang.String
indexOrConstraintName
private LanguageConnectionContext
lcc
private java.lang.String
tableName
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Fields inherited from class org.apache.derby.impl.sql.execute.BasicSortObserver
distinct, doClone
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Constructor Summary
Constructors Constructor Description UniqueWithDuplicateNullsIndexSortObserver(LanguageConnectionContext lcc, UUID constraintId, boolean doClone, boolean deferrable, boolean deferred, java.lang.String indexOrConstraintName, ExecRow execRow, boolean reuseWrappers, java.lang.String tableName)
Constructs an object of UniqueWithDuplicateNullsIndexSortObserver
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description boolean
deferrable()
Overridden by subclasses that observe sorters with uniqueness checking.boolean
deferred()
Overridden by subclasses that observe sorters with uniqueness checking.DataValueDescriptor[]
insertDuplicateKey(DataValueDescriptor[] in, DataValueDescriptor[] dup)
Methods to check if the duplicate key can be inserted or not.void
rememberDuplicate(DataValueDescriptor[] row)
Overridden by subclasses that observe sorters with uniqueness checking.-
Methods inherited from class org.apache.derby.impl.sql.execute.BasicSortObserver
addToFreeList, getArrayClone, insertNonDuplicateKey
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Field Detail
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indexOrConstraintName
private final java.lang.String indexOrConstraintName
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tableName
private final java.lang.String tableName
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deferrable
private final boolean deferrable
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deferred
private final boolean deferred
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lcc
private final LanguageConnectionContext lcc
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constraintId
private final UUID constraintId
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deferredDuplicates
private BackingStoreHashtable deferredDuplicates
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Constructor Detail
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UniqueWithDuplicateNullsIndexSortObserver
public UniqueWithDuplicateNullsIndexSortObserver(LanguageConnectionContext lcc, UUID constraintId, boolean doClone, boolean deferrable, boolean deferred, java.lang.String indexOrConstraintName, ExecRow execRow, boolean reuseWrappers, java.lang.String tableName)
Constructs an object of UniqueWithDuplicateNullsIndexSortObserver- Parameters:
lcc
- Language Connection contextconstraintId
- Id of the constraint (only used for deferrable constraints)doClone
- If true, then rows that are retained by the sorter will be cloned. This is needed if language is reusing row wrappers.deferrable
- deferrable constraintdeferred
- constraint mode is deferredindexOrConstraintName
- name of index of constraintexecRow
- ExecRow to use as source of clone for store.reuseWrappers
- Whether or not we can reuse the wrapperstableName
- name of the table
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Method Detail
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insertDuplicateKey
public DataValueDescriptor[] insertDuplicateKey(DataValueDescriptor[] in, DataValueDescriptor[] dup) throws StandardException
Methods to check if the duplicate key can be inserted or not. It throws exception if the duplicates has no null part in the key.- Specified by:
insertDuplicateKey
in interfaceSortObserver
- Overrides:
insertDuplicateKey
in classBasicSortObserver
- Parameters:
in
- new keydup
- the new key is duplicate of this key- Returns:
- DVD [] if there is at least one null in the key else throws StandardException
- Throws:
StandardException
- is the duplicate key has all non null parts
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deferred
public boolean deferred()
Description copied from interface:SortObserver
Overridden by subclasses that observe sorters with uniqueness checking.- Specified by:
deferred
in interfaceSortObserver
- Overrides:
deferred
in classBasicSortObserver
- Returns:
- true if constraint mode of the index's constraint is effectively deferred. Any SortObserver implementations that implement uniqueness checking need to keep track of this information.
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deferrable
public boolean deferrable()
Description copied from interface:SortObserver
Overridden by subclasses that observe sorters with uniqueness checking.- Specified by:
deferrable
in interfaceSortObserver
- Overrides:
deferrable
in classBasicSortObserver
- Returns:
- true if the index's constraint is deferrable. Any SortObserver implementations that implement uniqueness checking need to keep track of this information.
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rememberDuplicate
public void rememberDuplicate(DataValueDescriptor[] row) throws StandardException
Description copied from interface:SortObserver
Overridden by subclasses that observe sorters with uniqueness checking. Will be called by sorters iff deferrable() and deferred() and uniqueness violation, so implementations that sometimes return true to these must implement this method to save duplicate information till commit time.- Specified by:
rememberDuplicate
in interfaceSortObserver
- Overrides:
rememberDuplicate
in classBasicSortObserver
- Parameters:
row
- data of offending key- Throws:
StandardException
- standard error policy
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