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public interface OptimizablePredicate
OptimizablePredicate provides services for optimizing predicates in a query.
Method Summary | |
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boolean |
compareWithKnownConstant(Optimizable optTable,
boolean considerParameters)
Is this predicate a comparison with a known constant value? |
boolean |
equalsComparisonWithConstantExpression(Optimizable optTable)
Is this predicate an equality comparison with a constant expression? |
DataValueDescriptor |
getCompareValue(Optimizable optTable)
Get an Object representing the known constant value that the given Optimizable is being compared to. |
int |
getIndexPosition()
Get the position of the index column that this predicate restricts. |
JBitSet |
getReferencedMap()
Get the map of referenced tables for this OptimizablePredicate. |
int |
hasEqualOnColumnList(int[] baseColumnPositions,
Optimizable optTable)
Returns if the predicate involves an equal operator on one of the columns specified in the baseColumnPositions. |
boolean |
hasMethodCall()
Return whether or not an OptimizablePredicate contains a method call. |
boolean |
hasSubquery()
Return whether or not an OptimizablePredicate contains a subquery. |
boolean |
isQualifier()
Is this predicate a qualifier? |
boolean |
isStartKey()
Is this predicate a start key? |
boolean |
isStopKey()
Is this predicate a stop key? |
void |
markQualifier()
Tell the predicate that it is to be used as a qualifier in an index scan. |
void |
markStartKey()
Tell the predicate that it is to be used as a column in the start key value for an index scan. |
void |
markStopKey()
Tell the predicate that it is to be used as a column in the stop key value for an index scan. |
double |
selectivity(Optimizable optTable)
Get a (crude) estimate of the selectivity of this predicate. |
Method Detail |
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JBitSet getReferencedMap()
boolean hasSubquery()
boolean hasMethodCall()
void markStartKey()
boolean isStartKey()
void markStopKey()
boolean isStopKey()
void markQualifier()
boolean isQualifier()
boolean compareWithKnownConstant(Optimizable optTable, boolean considerParameters)
optTable
- The Optimizable that we want to know whether we
are comparing to a known constant.considerParameters
- Whether or not to consider parameters with defaults
as known constants.DataValueDescriptor getCompareValue(Optimizable optTable) throws StandardException
StandardException
- Thrown on errorboolean equalsComparisonWithConstantExpression(Optimizable optTable)
optTable
- The Optimizable for which we want to know whether
it is being equality-compared to a constant expression.int hasEqualOnColumnList(int[] baseColumnPositions, Optimizable optTable) throws StandardException
baseColumnPositions
- the column numbers on which the user wants
to check if the equality condition exists.optTable
- the table for which baseColumnPositions are given.
StandardException
double selectivity(Optimizable optTable) throws StandardException
optTable
- The Optimizable that this predicate restricts
StandardException
int getIndexPosition()
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Built on Thu 2012-03-29 21:53:33+0000, from revision ??? | ||||||||
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