org.aksw.sparqlify.database

Class ExprIndex

java.lang.Object

org.aksw.sparqlify.database.ExprIndex

public class ExprIndex
extends Object

TODO Clarify: Do I want disjunctive or conjunctive normal form? (a and b) or (c and d) or (a or b) and(c or d) ? I guess the former is better, as (a and not a) can be easily detected What happens if we allow conjunctions of disjunctive normal forms? ((a, b) or (c, d) AND ((x) or (y))) becomes (abx or aby or cdx or cdy) (so the cross product of the involved clauses) Maybe i could do virtual clauses: CrossJoinClause(Clauses ...) Hm, but with CNF it is easier to add new expressions.

Author:

Claus Stadler

Constructor Summary

Constructors

Constructor and Description
ExprIndex()
ExprIndex(ExprIndex parent)
ExprIndex(ExprIndex parent, Iterable<com.hp.hpl.jena.sparql.expr.Expr> exprs)
ExprIndex(Set<Dnf> dnfs)

Method Summary

Modifier and Type	Method and Description
void	addAll(Iterable<com.hp.hpl.jena.sparql.expr.Expr> exprs)
Set<Clause>	calcEffectiveClauses() This method is an ugly hack right, but I don't know where to better calculate it
void	calcEffectiveClauses(List<Dnf> dnfs, int index, Set<Clause> blacklist, Clause parentClause, Set<Clause> result) I use this method for getting constraints for finding view candidates
ExprIndex	filterByVars(Set<com.hp.hpl.jena.sparql.core.Var> requiredVars)
Set<Clause>	getAllClausesWith(com.hp.hpl.jena.sparql.core.Var var) Any clause containing a var means, that in order for the clause to evaluate to true, the expression it is involved must be true.
Set<Clause>	getAllSingleVarExprs(com.hp.hpl.jena.sparql.core.Var var)
Collection<Dnf>	getDnf()
Set<Clause>	getEffectiveClauses()
void	getEffectiveDnf(Collection<com.hp.hpl.jena.sparql.core.Var> vars)
ExprIndex	getParent()
Set<com.hp.hpl.jena.sparql.core.Var>	getVarsMentioned()
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

ExprIndex

public ExprIndex()

ExprIndex

public ExprIndex(ExprIndex parent)

ExprIndex

public ExprIndex(ExprIndex parent,
                 Iterable<com.hp.hpl.jena.sparql.expr.Expr> exprs)

ExprIndex

public ExprIndex(Set<Dnf> dnfs)

Method Detail

getEffectiveDnf

public void getEffectiveDnf(Collection<com.hp.hpl.jena.sparql.core.Var> vars)

calcEffectiveClauses

public void calcEffectiveClauses(List<Dnf> dnfs,
                                 int index,
                                 Set<Clause> blacklist,
                                 Clause parentClause,
                                 Set<Clause> result)

I use this method for getting constraints for finding view candidates

Parameters:

dnfs -

index -

dnfIndex -

blacklist -

depth -

parentClause -

result -

calcEffectiveClauses

public Set<Clause> calcEffectiveClauses()

This method is an ugly hack right, but I don't know where to better calculate it

Returns:

getEffectiveClauses

public Set<Clause> getEffectiveClauses()

getParent

public ExprIndex getParent()

getDnf

public Collection<Dnf> getDnf()

getVarsMentioned

public Set<com.hp.hpl.jena.sparql.core.Var> getVarsMentioned()

getAllClausesWith

public Set<Clause> getAllClausesWith(com.hp.hpl.jena.sparql.core.Var var)

Any clause containing a var means, that in order for the clause to evaluate to true, the expression it is involved must be true.

Parameters:

var -

Returns:

getAllSingleVarExprs

public Set<Clause> getAllSingleVarExprs(com.hp.hpl.jena.sparql.core.Var var)

addAll

public void addAll(Iterable<com.hp.hpl.jena.sparql.expr.Expr> exprs)

toString

public String toString()

Overrides:

toString in class Object

filterByVars

public ExprIndex filterByVars(Set<com.hp.hpl.jena.sparql.core.Var> requiredVars)