Package com.yahoo.search.predicate

Class PredicateIndexBuilder

java.lang.Object

com.yahoo.search.predicate.PredicateIndexBuilder

public class PredicateIndexBuilder
extends Object

A builder for PredicateIndex.

When creating a PredicateIndexBuilder, you must specify an arity. This is used for range features, and is a trade-off of index size vs. query speed. Higher arities gives larger index but faster search.

indexDocument(int, Predicate) takes a document id and a predicate to insert into the index. Predicates should be specified using the predicate syntax described in the documentation. Create the Predicate objects using Predicate.fromString(String).

Use build() to create an instance of PredicateIndex.

Author:

bjorncs

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	PredicateIndexBuilder.PredicateIndexStats	A collection of metrics about the currently built PredicateIndex.

Constructor Summary

Constructors

Constructor	Description
PredicateIndexBuilder(int arity)	Creates a PredicateIndexBuilder with default upper and lower bounds.
PredicateIndexBuilder(int arity, long lowerBound, long upperBound)	Creates a PredicateIndexBuilder.
PredicateIndexBuilder(Config config)	Creates a PredicateIndexBuilder based on a Config object.

Method Summary

Modifier and Type	Method	Description
PredicateIndex	build()
PredicateIndexBuilder.PredicateIndexStats	getStats()	Retrieves metrics about the current index.
int	getZeroConstraintDocCount()
void	indexDocument(int docId, com.yahoo.document.predicate.Predicate predicate)	Indexes a predicate with the given id.

Methods inherited from class java.lang.Object

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

Constructor Details

PredicateIndexBuilder

public PredicateIndexBuilder(int arity)

Creates a PredicateIndexBuilder with default upper and lower bounds.

Parameters:

arity - the arity to use when indexing range predicates. Small arity gives smaller index, but more expensive searches.

PredicateIndexBuilder

public PredicateIndexBuilder(int arity,
 long lowerBound,
 long upperBound)

Creates a PredicateIndexBuilder. Limiting the range of possible values in range predicates reduces index size and increases search performance.

Parameters:

arity - the arity to use when indexing range predicates. Small arity gives smaller index, but more expensive searches.

lowerBound - the lower bound for the range of values used by range predicates

upperBound - the upper bound for the range of values used by range predicates

PredicateIndexBuilder

public PredicateIndexBuilder(Config config)

Creates a PredicateIndexBuilder based on a Config object.

Parameters:

config - configuration for the PredicateIndexBuilder

Method Details

indexDocument

public void indexDocument(int docId,
 com.yahoo.document.predicate.Predicate predicate)

Indexes a predicate with the given id.

Parameters:

docId - a 32-bit document id, returned in the Hit objects when the predicate matches

predicate - the predicate to index

build

public PredicateIndex build()

getZeroConstraintDocCount

public int getZeroConstraintDocCount()

getStats

public PredicateIndexBuilder.PredicateIndexStats getStats()

Retrieves metrics about the current index.

Returns:

an object containing metrics