| java.lang.Object
 org.apache.derbyTesting.unitTests.store.QualifierUtil
| Constructor Summary | |
| public | QualifierUtil(int column_id, DataValueDescriptor key_val, int operator, boolean negateCompareResult, boolean orderedNulls, boolean unknownRV)
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| QualifierUtil | | public QualifierUtil(int column_id, DataValueDescriptor key_val, int operator, boolean negateCompareResult, boolean orderedNulls, boolean unknownRV)(Code) | | Constuctor
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| clearOrderableCache | | public void clearOrderableCache()(Code) | | 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
See Also: Qualifier.getUnknownRV |
| getColumnId | | public int getColumnId()(Code) | | Get the id of the column to be qualified. *
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| reinitialize | | public void reinitialize()(Code) | | 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.
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