Module org.apache.jena.arq

Package org.apache.jena.sparql.engine.optimizer

Class StatsMatcher

java.lang.Object

org.apache.jena.sparql.engine.optimizer.StatsMatcher

public final class StatsMatcher
extends Object

Stats format:

 (stats
    (meta ...)
    ((S P O) weight)
    (<predicate uri> weight)
 )
 

where S, P, O is a URI, variable, literal or one of the words ANY (matches anything), VAR (matches a variable), TERM (matches a fixed URI, or literal), URI, BNODE, LITERAL (matches one of these types).

Field Summary

Fields

Modifier and Type	Field	Description
static final String	COUNT
static final String	META
static final Item	OTHER
static final String	STATS
static final double	weightPO
static final double	weightPO_small
static final double	weightSP
static final double	weightSP_small
static final double	weightTypeO
static final double	weightTypeO_small

Constructor Summary

Constructors

Constructor	Description
StatsMatcher()
StatsMatcher(String filename)
StatsMatcher(Item stats)

Method Summary

Modifier and Type	Method	Description
void	addPattern(Pattern pattern)
void	addPatterns(org.apache.jena.graph.Node predicate, double numProp)	Add patterns based solely on the predicate count and some guessing
void	addPatternsSmall(org.apache.jena.graph.Node predicate, double numProp)	Add patterns based solely on the predicate count and some guessing for a small graph (less than a few thousand triples)
double	match(org.apache.jena.graph.Triple t)
double	match(PatternTriple pTriple)
double	match(Item subj, Item pred, Item obj)	Return the matching weight for the first triple match found, else apply default value for fixed, unknown predicate, else return NOMATCH
void	printSSE(OutputStream ps)
String	toString()

Methods inherited from class java.lang.Object

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

Field Details

STATS

public static final String STATS

See Also:

• Constant Field Values

META

public static final String META

See Also:

• Constant Field Values

COUNT

public static final String COUNT

See Also:

• Constant Field Values

OTHER

public static final Item OTHER

weightSP

public static final double weightSP

See Also:

• Constant Field Values

weightPO

public static final double weightPO

See Also:

• Constant Field Values

weightTypeO

public static final double weightTypeO

See Also:

• Constant Field Values

weightSP_small

public static final double weightSP_small

See Also:

• Constant Field Values

weightPO_small

public static final double weightPO_small

See Also:

• Constant Field Values

weightTypeO_small

public static final double weightTypeO_small

See Also:

• Constant Field Values

Constructor Details

StatsMatcher

public StatsMatcher()

StatsMatcher

public StatsMatcher(String filename)

StatsMatcher

public StatsMatcher(Item stats)

Method Details

addPatterns

public void addPatterns(org.apache.jena.graph.Node predicate,
 double numProp)

Add patterns based solely on the predicate count and some guessing

addPatternsSmall

public void addPatternsSmall(org.apache.jena.graph.Node predicate,
 double numProp)

Add patterns based solely on the predicate count and some guessing for a small graph (less than a few thousand triples)

addPattern

public void addPattern(Pattern pattern)

match

public double match(org.apache.jena.graph.Triple t)

match

public double match(PatternTriple pTriple)

match

public double match(Item subj,
 Item pred,
 Item obj)

Return the matching weight for the first triple match found, else apply default value for fixed, unknown predicate, else return NOMATCH

toString

public String toString()

Overrides:

toString in class Object

printSSE

public void printSSE(OutputStream ps)