Class UTFQualifier
java.lang.Object
org.apache.derby.impl.store.access.UTFQualifier
- All Implemented Interfaces:
Qualifier
-
Field Summary
FieldsFields inherited from interface org.apache.derby.iapi.store.access.Qualifier
CONSTANT, QUERY_INVARIANT, SCAN_INVARIANT, VARIANT
-
Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionvoid
Clear the DataValueDescriptor cache, if one exists.int
Get the id of the column to be qualified.int
Get the operator to use in the comparison.Get the value that the column is to be compared to.boolean
Get the getOrderedNulls argument to use in the comparison.boolean
Get the getOrderedNulls argument to use in the comparison.boolean
Determine if the result from the compare operation is to be negated.void
This method reinitializes all the state of the Qualifier.
-
Field Details
-
value
-
columnId
private int columnId
-
-
Constructor Details
-
UTFQualifier
-
-
Method Details
-
getColumnId
public int getColumnId()Get the id of the column to be qualified.- Specified by:
getColumnId
in interfaceQualifier
-
getOrderable
Get the value that the column is to be compared to.- Specified by:
getOrderable
in interfaceQualifier
-
getOperator
public int getOperator()Get the operator to use in the comparison.- Specified by:
getOperator
in interfaceQualifier
- See Also:
-
negateCompareResult
public boolean negateCompareResult()Determine if the result from the compare operation is to be negated.If true then only rows which fail the compare operation will qualify.
- Specified by:
negateCompareResult
in interfaceQualifier
- See Also:
-
getOrderedNulls
public boolean getOrderedNulls()Description copied from interface:Qualifier
Get the getOrderedNulls argument to use in the comparison.- Specified by:
getOrderedNulls
in interfaceQualifier
- See Also:
-
getUnknownRV
public boolean getUnknownRV()Get the getOrderedNulls argument to use in the comparison.- Specified by:
getUnknownRV
in interfaceQualifier
- See Also:
-
clearOrderableCache
public void clearOrderableCache()Clear the DataValueDescriptor cache, if one exists. (The DataValueDescriptor can be 1 of 3 types: o VARIANT - cannot be cached as its value can vary within a scan o SCAN_INVARIANT - can be cached within a scan as its value will not change within a scan o QUERY_INVARIANT- can be cached across the life of the query as its value will never change o CONSTANT - can be cached across executions- Specified by:
clearOrderableCache
in interfaceQualifier
- See Also:
-
reinitialize
public void reinitialize()This method reinitializes all the state of the Qualifier. It is used to distinguish between resetting something that is query invariant and something that is constant over every execution of a query. Basically, clearOrderableCache() will only clear out its cache if it is a VARIANT or SCAN_INVARIANT value. However, each time a query is executed, the QUERY_INVARIANT qualifiers need to be reset.- Specified by:
reinitialize
in interfaceQualifier
-