org.apache.solr.search

Class LuceneQueryOptimizer

java.lang.Object

org.apache.solr.search.LuceneQueryOptimizer

class LuceneQueryOptimizer
extends java.lang.Object

Utility which converts certain query clauses into QueryFilters and caches these. Only required TermQuerys whose boost is zero and whose term occurs in at least a certain fraction of documents are converted to cached filters. This accelerates query constraints like language, document format, etc., which do not affect ranking but might otherwise slow search considerably.

Field Summary

Fields

Modifier and Type	Field and Description
private java.util.LinkedHashMap	cache
private float	threshold

Constructor Summary

Constructors

Constructor and Description
LuceneQueryOptimizer(int cacheSize, float threshold) Construct an optimizer that caches and uses filters for required TermQuerys whose boost is zero.

Method Summary

Modifier and Type	Method and Description
org.apache.lucene.search.TopDocs	optimize(org.apache.lucene.search.BooleanQuery original, org.apache.lucene.search.Searcher searcher, int numHits, org.apache.lucene.search.Query[] queryOut, org.apache.lucene.search.Filter[] filterOut)

Methods inherited from class java.lang.Object

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

Field Detail

cache

private java.util.LinkedHashMap cache

threshold

private float threshold

Constructor Detail

LuceneQueryOptimizer

public LuceneQueryOptimizer(int cacheSize,
                            float threshold)

Construct an optimizer that caches and uses filters for required TermQuerys whose boost is zero.

Parameters:

cacheSize - the number of QueryFilters to cache

threshold - the fraction of documents which must contain term

Method Detail

optimize

public org.apache.lucene.search.TopDocs optimize(org.apache.lucene.search.BooleanQuery original,
                                                 org.apache.lucene.search.Searcher searcher,
                                                 int numHits,
                                                 org.apache.lucene.search.Query[] queryOut,
                                                 org.apache.lucene.search.Filter[] filterOut)
                                          throws java.io.IOException

Throws:

java.io.IOException