fix FuzzyQuery in keyword field will use IndexOrDocValuesQuery when both of index and doc_value are true

CHANGELOG.md

@@ -41,6 +41,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Write shard level metadata blob when snapshotting searchable snapshot indexes ([#13190](https://github.com/opensearch-project/OpenSearch/pull/13190))
 - Fix aggs result of NestedAggregator with sub NestedAggregator ([#13324](https://github.com/opensearch-project/OpenSearch/pull/13324))
 - Add ListPitInfo::getKeepAlive() getter ([#14495](https://github.com/opensearch-project/OpenSearch/pull/14495))
+- Fix FuzzyQuery in keyword field will use IndexOrDocValuesQuery when both of index and doc_value are true ([#14378](https://github.com/opensearch-project/OpenSearch/pull/14378))
 
 ### Security
 

server/src/main/java/org/opensearch/index/mapper/KeywordFieldMapper.java

@@ -549,7 +549,7 @@ public Query fuzzyQuery(
                 );
             }
             if (isSearchable() && hasDocValues()) {
-                Query indexQuery = super.fuzzyQuery(value, fuzziness, prefixLength, maxExpansions, transpositions, context);
+                Query indexQuery = super.fuzzyQuery(value, fuzziness, prefixLength, maxExpansions, transpositions, method, context);
                 Query dvQuery = super.fuzzyQuery(
                     value,
                     fuzziness,

server/src/main/java/org/opensearch/index/mapper/StringFieldType.java

@@ -55,6 +55,7 @@
 import java.util.regex.Pattern;
 
 import static org.opensearch.search.SearchService.ALLOW_EXPENSIVE_QUERIES;
+import static org.apache.lucene.search.FuzzyQuery.defaultRewriteMethod;
 
 /** Base class for {@link MappedFieldType} implementations that use the same
  * representation for internal index terms as the external representation so
@@ -102,6 +103,35 @@
         );
     }
 
+    @Override
+    public Query fuzzyQuery(
+        Object value,
+        Fuzziness fuzziness,
+        int prefixLength,
+        int maxExpansions,
+        boolean transpositions,
+        MultiTermQuery.RewriteMethod method,
+        QueryShardContext context
+    ) {
+        if (!context.allowExpensiveQueries()) {
+            throw new OpenSearchException(
+                "[fuzzy] queries cannot be executed when '" + ALLOW_EXPENSIVE_QUERIES.getKey() + "' is set to false."
+            );
+        }
+        failIfNotIndexed();
+        if (method == null) {
+            method = defaultRewriteMethod(maxExpansions);
+        }
+        return new FuzzyQuery(
+            new Term(name(), indexedValueForSearch(value)),
+            fuzziness.asDistance(BytesRefs.toString(value)),
+            prefixLength,
+            maxExpansions,
+            transpositions,
+            method
+        );
+    }
+
     @Override
     public Query prefixQuery(String value, MultiTermQuery.RewriteMethod method, boolean caseInsensitive, QueryShardContext context) {
         if (context.allowExpensiveQueries() == false) {

server/src/main/java/org/opensearch/index/query/FuzzyQueryBuilder.java

@@ -357,7 +357,7 @@ protected Query doToQuery(QueryShardContext context) throws IOException {
             throw new IllegalStateException("Rewrite first");
         }
         String rewrite = this.rewrite;
-        Query query = fieldType.fuzzyQuery(value, fuzziness, prefixLength, maxExpansions, transpositions, context);
+        Query query = fieldType.fuzzyQuery(value, fuzziness, prefixLength, maxExpansions, transpositions, null, context);
         if (query instanceof MultiTermQuery) {
             MultiTermQuery.RewriteMethod rewriteMethod = QueryParsers.parseRewriteMethod(rewrite, null, LoggingDeprecationHandler.INSTANCE);
             QueryParsers.setRewriteMethod((MultiTermQuery) query, rewriteMethod);

server/src/test/java/org/opensearch/index/mapper/KeywordFieldTypeTests.java

@@ -263,8 +263,11 @@ public void testRegexpQuery() {
     public void testFuzzyQuery() {
         MappedFieldType ft = new KeywordFieldType("field");
         assertEquals(
-            new FuzzyQuery(new Term("field", "foo"), 2, 1, 50, true),
-            ft.fuzzyQuery("foo", Fuzziness.fromEdits(2), 1, 50, true, MOCK_QSC)
+            new IndexOrDocValuesQuery(
+                new FuzzyQuery(new Term("field", "foo"), 2, 1, 50, true),
+                new FuzzyQuery(new Term("field", "foo"), 2, 1, 50, true, MultiTermQuery.DOC_VALUES_REWRITE)
+            ),
+            ft.fuzzyQuery("foo", Fuzziness.fromEdits(2), 1, 50, true, null, MOCK_QSC)
         );
 
         Query indexExpected = new FuzzyQuery(new Term("field", "foo"), 2, 1, 50, true);