The PredicateList class describes two lists of predicates
to estimate the selectivity factor. Instances of this class are used
as input to UnfencedGenericServer.getSelectivity, the selectivity
estimation function.
The two predicate lists are:
- a list of predicates that selectivity is solicited for (P)
- a list of previously applied predicates (AP)
The result selectivity is conditional selectivity: selectivity
(P/AP). If you need unconditional selectivity, the AP can be null.
If the implementation cannot support this framework, the implementation
can be set to ignore the AP. The lists of predicates are similar to
the list of predicates in the Request class and are manipulated with
similar methods.
The PredicateList class is one of the planning
classes for the Java™ API.
Package
com.ibm.db2.wrapper
Constructors and methods
This class does
not contain constructors.
