ch.ethz.mxquery.opt.expr
Class CTerm

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

All Implemented Interfaces:

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

public final class CTerm
extends Term

This term presents a conjunction term. It also implements the logic for conjunctions to allow short circuit

Field Summary

boolean

indexed

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

CTerm()

Method Summary

void	addLiteral(Literal literal) Adds a new literal to the conjunction term
int	evaluate(int level) Evaluates the conjunction term up to a certain dependency level.
CompareLiteralIndexSchema	getIndexSchema(int indexNb)
Literal	getLiteral(int i) Returns the literal from position i from this conjunction term
boolean	isCompleteIndexable() Checks if the CTerm is complete indexable
boolean	isIndexed() Returns if this conjunction term is indexed
int	reset(int level) Resets the logical unit up to a certain degree on variable dependency
void	setIndexed(boolean indexed) Sets if this conjunction term is indexed

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

add, addAll, clone, get, size, sort, 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

Field Detail

indexed

public boolean indexed

Constructor Detail

CTerm

public CTerm()

Method Detail

isIndexed

public boolean isIndexed()

Returns if this conjunction term is indexed

Returns:

true if indexed

setIndexed

public void setIndexed(boolean indexed)

Sets if this conjunction term is indexed

addLiteral

public void addLiteral(Literal literal)

Adds a new literal to the conjunction term

Parameters:

literal -

getLiteral

public Literal getLiteral(int i)

Returns the literal from position i from this conjunction term

Parameters:

i - position of the literal

evaluate

public int evaluate(int level)
             throws MXQueryException

Evaluates the conjunction term up to a certain dependency level. Additional this evaluate makes use of short circuit

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)

Description copied from class: LogicalUnit

Resets the logical unit up to a certain degree on variable dependency

Specified by:

reset in class Term

Returns:

UNKNOWN, TRUE or FALSE

getIndexSchema

public CompareLiteralIndexSchema getIndexSchema(int indexNb)

isCompleteIndexable

public boolean isCompleteIndexable()

Checks if the CTerm is complete indexable

Returns:

true if all components can be indexed, false otherwise