ES\QL: Fix scoring for non full text functions (#124540) (#125104)

(cherry picked from commit 7950751)

# Conflicts:
#	x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/session/QueryBuilderResolver.java
#	x-pack/plugin/esql/src/test/java/org/elasticsearch/xpack/esql/expression/function/fulltext/QueryStringTests.java
#	x-pack/plugin/esql/src/test/java/org/elasticsearch/xpack/esql/optimizer/LocalPhysicalPlanOptimizerTests.java

Author: carlosdelest

docs/changelog/124540.yaml

@@ -0,0 +1,5 @@
+pr: 124540
+summary: "ES|QL: Fix scoring for full text functions"
+area: ES|QL
+type: bug
+issues: []

x-pack/plugin/esql-core/src/main/java/org/elasticsearch/xpack/esql/core/querydsl/query/BoolQuery.java

@@ -43,13 +43,14 @@ public BoolQuery(Source source, boolean isAnd, List<Query> queries) {
     }
 
     @Override
-    public QueryBuilder asBuilder() {
+    protected QueryBuilder asBuilder() {
         BoolQueryBuilder boolQuery = boolQuery();
         for (Query query : queries) {
+            QueryBuilder queryBuilder = query.toQueryBuilder();
             if (isAnd) {
-                boolQuery.must(query.asBuilder());
+                boolQuery.must(queryBuilder);
             } else {
-                boolQuery.should(query.asBuilder());
+                boolQuery.should(queryBuilder);
             }
         }
         return boolQuery;
@@ -94,4 +95,9 @@ public Query negate(Source source) {
         }
         return new BoolQuery(source, isAnd == false, negated);
     }
+
+    @Override
+    public boolean scorable() {
+        return true;
+    }
 }

x-pack/plugin/esql-core/src/main/java/org/elasticsearch/xpack/esql/core/querydsl/query/ExistsQuery.java

@@ -21,7 +21,7 @@ public ExistsQuery(Source source, String name) {
     }
 
     @Override
-    public QueryBuilder asBuilder() {
+    protected QueryBuilder asBuilder() {
         return existsQuery(name);
     }
 

x-pack/plugin/esql-core/src/main/java/org/elasticsearch/xpack/esql/core/querydsl/query/GeoDistanceQuery.java

@@ -45,7 +45,7 @@ public double distance() {
     }
 
     @Override
-    public QueryBuilder asBuilder() {
+    protected QueryBuilder asBuilder() {
         return QueryBuilders.geoDistanceQuery(field).distance(distance, DistanceUnit.METERS).point(lat, lon);
     }
 

x-pack/plugin/esql-core/src/main/java/org/elasticsearch/xpack/esql/core/querydsl/query/MatchAll.java

@@ -17,7 +17,7 @@ public MatchAll(Source source) {
     }
 
     @Override
-    public QueryBuilder asBuilder() {
+    protected QueryBuilder asBuilder() {
         return matchAllQuery();
     }
 

x-pack/plugin/esql-core/src/main/java/org/elasticsearch/xpack/esql/core/querydsl/query/NotQuery.java

@@ -32,8 +32,8 @@ public Query child() {
     }
 
     @Override
-    public QueryBuilder asBuilder() {
-        return boolQuery().mustNot(child.asBuilder());
+    protected QueryBuilder asBuilder() {
+        return boolQuery().mustNot(child.toQueryBuilder());
     }
 
     @Override

x-pack/plugin/esql-core/src/main/java/org/elasticsearch/xpack/esql/core/querydsl/query/PrefixQuery.java

@@ -34,7 +34,7 @@ public String query() {
     }
 
     @Override
-    public QueryBuilder asBuilder() {
+    protected QueryBuilder asBuilder() {
         return prefixQuery(field, query).caseInsensitive(caseInsensitive);
     }
 

x-pack/plugin/esql-core/src/main/java/org/elasticsearch/xpack/esql/core/querydsl/query/Query.java

@@ -28,6 +28,10 @@
  * </p>
  */
 public abstract class Query {
+
+    // Boosting used to remove scoring from queries that don't contribute to it
+    public static final float NO_SCORE_BOOST = 0.0f;
+
     private final Source source;
 
     protected Query(Source source) {
@@ -46,9 +50,20 @@ public Source source() {
 
     /**
      * Convert to an Elasticsearch {@link QueryBuilder} all set up to execute
-     * the query.
+     * the query. This ensures that queries have appropriate boosting for scoring.
+     */
+    public final QueryBuilder toQueryBuilder() {
+        QueryBuilder builder = asBuilder();
+        if (scorable() == false) {
+            builder = unscore(builder);
+        }
+        return builder;
+    }
+
+    /**
+     * Used internally to convert to retrieve a {@link QueryBuilder} by queries.
      */
-    public abstract QueryBuilder asBuilder();
+    protected abstract QueryBuilder asBuilder();
 
     /**
      * Used by {@link Query#toString()} to produce a pretty string.
@@ -85,4 +100,18 @@ public String toString() {
     public Query negate(Source source) {
         return new NotQuery(source, this);
     }
+
+    /**
+     * Defines whether a query should contribute to the overall score
+     */
+    public boolean scorable() {
+        return false;
+    }
+
+    /**
+     * Removes score from a query builder, so score is not affected by the query
+     */
+    public static QueryBuilder unscore(QueryBuilder builder) {
+        return builder.boost(NO_SCORE_BOOST);
+    }
 }

x-pack/plugin/esql-core/src/main/java/org/elasticsearch/xpack/esql/core/querydsl/query/QueryStringQuery.java

@@ -64,7 +64,7 @@ public QueryStringQuery(Source source, String query, Map<String, Float> fields,
     }
 
     @Override
-    public QueryBuilder asBuilder() {
+    protected QueryBuilder asBuilder() {
         final QueryStringQueryBuilder queryBuilder = QueryBuilders.queryStringQuery(query);
         queryBuilder.fields(fields);
         options.forEach((k, v) -> {
@@ -108,4 +108,9 @@ public boolean equals(Object obj) {
     protected String innerToString() {
         return fields + ":" + query;
     }
+
+    @Override
+    public boolean scorable() {
+        return true;
+    }
 }

x-pack/plugin/esql-core/src/main/java/org/elasticsearch/xpack/esql/core/querydsl/query/RangeQuery.java

@@ -77,7 +77,7 @@ public ZoneId zoneId() {
     }
 
     @Override
-    public QueryBuilder asBuilder() {
+    protected QueryBuilder asBuilder() {
         RangeQueryBuilder queryBuilder = rangeQuery(field).from(lower, includeLower).to(upper, includeUpper);
         if (Strings.hasText(format)) {
             queryBuilder.format(format);