net.ontopia.topicmaps.query.impl.utils

Class QueryOptimizer.AddTypeToRolePlayer

java.lang.Object

net.ontopia.topicmaps.query.impl.utils.QueryOptimizer.AbstractQueryOptimizer

net.ontopia.topicmaps.query.impl.utils.QueryOptimizer.AddTypeToRolePlayer

All Implemented Interfaces:

QueryOptimizerIF

Enclosing class:

QueryOptimizer

public static class QueryOptimizer.AddTypeToRolePlayer
extends QueryOptimizer.AbstractQueryOptimizer

INTERNAL:

Optimizes the role-player() predicate when the type of the role is known from a type() predicate in the same query. Typical usage is:

 role-player($R1, fixed-point),
 association-role($A, $R1),
 association-role($A, $R2),
 $R1 /= $R2,
 role-player($R2, $OTHER),
 type($R1, required-type)?
 

What's really needed for the optimization to kick in is two things:

• In the role-player($A, $B) predicate $A must be unbound and $B must be bound
• In the type($C, $D) predicate the $C must match $A, and $D must be bound when the role-player() runs, and not by the type() predicate

Constructor Summary

Constructors

Constructor and Description
AddTypeToRolePlayer()

Method Summary

Modifier and Type	Method and Description
void	optimize(TologQuery query, QueryContext context)

Methods inherited from class net.ontopia.topicmaps.query.impl.utils.QueryOptimizer.AbstractQueryOptimizer

optimize, optimize

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

AddTypeToRolePlayer

public AddTypeToRolePlayer()

Method Detail

optimize

public void optimize(TologQuery query,
                     QueryContext context)

Specified by:

optimize in interface QueryOptimizerIF

Overrides:

optimize in class QueryOptimizer.AbstractQueryOptimizer