[GitHub] [lucene] rmuir commented on a diff in pull request #12089: [DRAFT] Explore TermInSet Query that "self optimizes"

[GitBox <gi...@apache.org>]

rmuir commented on code in PR #12089:
URL: https://github.com/apache/lucene/pull/12089#discussion_r1072830614


##########
lucene/sandbox/src/java/org/apache/lucene/sandbox/queries/TermInSetQuery.java:
##########
@@ -0,0 +1,527 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.lucene.sandbox.queries;
+
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.Objects;
+import java.util.Set;
+import org.apache.lucene.index.DocValues;
+import org.apache.lucene.index.DocValuesType;
+import org.apache.lucene.index.FieldInfo;
+import org.apache.lucene.index.LeafReader;
+import org.apache.lucene.index.LeafReaderContext;
+import org.apache.lucene.index.PostingsEnum;
+import org.apache.lucene.index.SortedDocValues;
+import org.apache.lucene.index.SortedSetDocValues;
+import org.apache.lucene.index.Term;
+import org.apache.lucene.index.TermState;
+import org.apache.lucene.index.Terms;
+import org.apache.lucene.index.TermsEnum;
+import org.apache.lucene.search.ConstantScoreScorer;
+import org.apache.lucene.search.ConstantScoreWeight;
+import org.apache.lucene.search.DisiPriorityQueue;
+import org.apache.lucene.search.DisiWrapper;
+import org.apache.lucene.search.DocIdSetIterator;
+import org.apache.lucene.search.IndexSearcher;
+import org.apache.lucene.search.MatchNoDocsQuery;
+import org.apache.lucene.search.Query;
+import org.apache.lucene.search.QueryVisitor;
+import org.apache.lucene.search.ScoreMode;
+import org.apache.lucene.search.Scorer;
+import org.apache.lucene.search.ScorerSupplier;
+import org.apache.lucene.search.TermQuery;
+import org.apache.lucene.search.TwoPhaseIterator;
+import org.apache.lucene.search.Weight;
+import org.apache.lucene.util.BytesRef;
+import org.apache.lucene.util.DocIdSetBuilder;
+import org.apache.lucene.util.LongBitSet;
+import org.apache.lucene.util.PriorityQueue;
+
+public class TermInSetQuery extends Query {
+  // TODO: tunable coefficients. need to actually tune them (or maybe these are too complex and not
+  // useful)
+  private static final double J = 1.0;
+  private static final double K = 1.0;
+  // L: postings lists under this threshold will always be "pre-processed" into a bitset
+  private static final int L = 512;
+  // M: max number of clauses we'll manage/check during scoring (these remain "unprocessed")
+  private static final int M = Math.min(IndexSearcher.getMaxClauseCount(), 64);
+
+  private final String field;
+  // TODO: Not particularly memory-efficient; could use prefix-coding here but sorting isn't free
+  private final BytesRef[] terms;

Review Comment:
   but this is really bad for performance to be unsorted: it means we do a bunch of random access lookups in the terms dictionaries: looping over these unsorted terms and doing seekExact, looping over these unsorted terms and doing lookupOrd that could instead easily be sequential/more friendly.
   
   Given that sometimes looking up all the terms is a very heavy cost for this thing, calling `Arrays.sort()` in the ctor seems like an easy-win/no-brainer. As is the prefix-coding to keep the RAM usage lower in the worst-case. 



-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: issues-unsubscribe@lucene.apache.org

For queries about this service, please contact Infrastructure at:
users@infra.apache.org


---------------------------------------------------------------------
To unsubscribe, e-mail: issues-unsubscribe@lucene.apache.org
For additional commands, e-mail: issues-help@lucene.apache.org