ch.ethz.mxquery.opt.expr
Class DTerm

java.lang.Object
  ch.ethz.mxquery.opt.expr.LogicalUnit
      ch.ethz.mxquery.opt.expr.Term
          ch.ethz.mxquery.opt.expr.DTerm

All Implemented Interfaces:

Traversable, java.lang.Cloneable, java.lang.Comparable

public final class DTerm
extends Term

Represents a disjunction term, with consists of conjunction terms - needed for the max indexes

Field Summary

Fields inherited from class ch.ethz.mxquery.opt.expr.LogicalUnit

DEPENDENCY_END, DEPENDENCY_NO, DEPENDENCY_START, DEPENDENCY_STARTEND, INDEX_IMPOSSIBLE, INDEX_POSSIBLE, INDEX_RECOMMEND, RESET, RESULT_FALSE, RESULT_TRUE, RESULT_UNKNOWN

Constructor Summary

DTerm()

Method Summary

void	addAll(DTerm dList) Combines two disjunctin terms to one
void	addCTerm(CTerm cList) Adds a new conjunction term
DTerm	combineLists(DTerm l2) Merges two dList in the form that every element from one list is combined with every element in the second list.
int	evaluate(int level) Checks the condition and also removes false literals
CTerm	getCTerm(int i) Returns the conjunction term at position i
int	reset(int level) Resets the evaluation of the conjunction term up to a certain level of dependency
void	sort() Sortts the conjunctions terms according to the dependencies

Methods inherited from class ch.ethz.mxquery.opt.expr.Term

add, addAll, clone, get, size, traverse

Methods inherited from class ch.ethz.mxquery.opt.expr.LogicalUnit

addDependency, compareTo, getDependency, getDependencyName, getDependencyNb, getResult, isDependendOnEnd, isDependendOnStart, isIndexable, isLowerDependency, isLowerOrEqualDependency, setDependency, setIndexable

Methods inherited from class java.lang.Object

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

Constructor Detail

DTerm

public DTerm()

Method Detail

addCTerm

public void addCTerm(CTerm cList)

Adds a new conjunction term

Parameters:

cList -

addAll

public void addAll(DTerm dList)

Combines two disjunctin terms to one

Parameters:

dList -

getCTerm

public CTerm getCTerm(int i)

Returns the conjunction term at position i

Parameters:

i -

Returns:

the i-th CTerm

sort

public void sort()

Sortts the conjunctions terms according to the dependencies

Overrides:

sort in class Term

combineLists

public DTerm combineLists(DTerm l2)

Merges two dList in the form that every element from one list is combined with every element in the second list. If one of the lists is empty, the other list is returned;

Parameters:

l2 -

Returns:

the combination of the lists

evaluate

public int evaluate(int level)
             throws MXQueryException

Checks the condition and also removes false literals

Specified by:

evaluate in class Term

Parameters:

level - Up to this dependency level the unit is evaluated

Returns:

false, true or unknown

Throws:

MXQueryException

reset

public int reset(int level)

Resets the evaluation of the conjunction term up to a certain level of dependency

Specified by:

reset in class Term

Returns:

UNKNOWN, TRUE or FALSE