ESQL: Push down StartsWith and EndsWith functions to Lucene

docs/changelog/123381.yaml

@@ -1,5 +1,5 @@
 pr: 123381
-summary: Push down `StarsWith` and `EndsWith` functions to Lucene
+summary: Push down `StartsWith` and `EndsWith` functions to Lucene
 area: ES|QL
 type: enhancement
 issues:

x-pack/plugin/esql/qa/testFixtures/src/main/resources/string.csv-spec

@@ -1279,6 +1279,99 @@ description:text
 ;
 
 
+lucenePushdownMultipleWhere
+
+from hosts
+| where starts_with(host, "bet")
+| keep host, host_group
+| sort host, host_group
+| where ends_with(host_group, "cluster");
+
+host:keyword | host_group:text
+beta         | Kubernetes cluster
+beta         | Kubernetes cluster
+beta         | Kubernetes cluster
+;
+
+lucenePushdownMultipleIndices
+
+from airports* metadata _index
+| where starts_with(name::keyword, "Sahn") and ends_with(abbrev, "UH")
+| keep abbrev, name, _index
+| sort abbrev, name, _index;
+
+abbrev:keyword | name:text | _index:keyword
+LUH            | Sahnewal  | airports
+LUH            | Sahnewal  | airports_mp
+LUH            | Sahnewal  | airports_no_doc_values
+LUH            | Sahnewal  | airports_not_indexed
+LUH            | Sahnewal  | airports_not_indexed_nor_doc_values
+LUH            | Sahnewal  | airports_web
+;
+
+lucenePushdownOr
+
+from airports
+| where starts_with(name::keyword, "Sahn") or ends_with(abbrev, "UH")
+| keep abbrev, name
+| sort abbrev, name;
+
+abbrev:keyword | name:text
+AUH            | Abu Dhabi Int'l  
+LUH            | Sahnewal         
+RUH            | King Khalid Int'l
+;
+
+lucenePushdownMultipleOr
+
+from airports
+| where starts_with(name::keyword, "Sahn") or ends_with(abbrev, "UH") or starts_with(abbrev, "OOL")
+| keep abbrev, name
+| sort abbrev, name;
+
+abbrev:keyword | name:text
+AUH            | Abu Dhabi Int'l
+LUH            | Sahnewal
+OOL            | Gold Coast
+RUH            | King Khalid Int'l
+;
+
+lucenePushdownMultipleAnd
+
+from airports metadata _index
+| where starts_with(name::keyword, "Sahn") and ends_with(abbrev, "UH")
+| where ends_with(name::keyword, "al")
+| keep abbrev, name, _index
+| sort abbrev, name, _index;
+
+abbrev:keyword | name:text | _index:keyword
+LUH            | Sahnewal  | airports
+;
+
+lucenePushdownMixAndOr
+
+from airports
+| where starts_with(name::keyword, "Sahn") and (starts_with(name::keyword, "Abc") or ends_with(abbrev, "UH"))
+| keep abbrev, name, scalerank
+| sort abbrev, name;
+
+abbrev:keyword | name:text | scalerank:integer
+LUH            | Sahnewal  | 9
+;
+
+lucenePushdownMixOrAnd
+
+from airports* metadata _index
+| where starts_with(name::keyword, "Sahn") or (starts_with(abbrev, "G") and ends_with(name::keyword, "Falls Int'l"))
+| where ends_with(_index, "airports")
+| keep abbrev, name, scalerank, _index
+| sort abbrev;
+
+abbrev:keyword | name:text         | scalerank:integer | _index:keyword
+GTF            | Great Falls Int'l | 8                 | airports      
+LUH            | Sahnewal          | 9                 | airports
+;
+
 toLowerRow#[skip:-8.12.99]
 // tag::to_lower[]
 ROW message = "Some Text"

x-pack/plugin/esql/src/test/java/org/elasticsearch/xpack/esql/optimizer/PhysicalPlanOptimizerTests.java

@@ -1132,6 +1132,45 @@ public void testPushMultipleBinaryLogicFilters() {
         assertThat(rq.to(), nullValue());
     }
 
+    public void testPushMultipleFunctions() {
+        var plan = physicalPlan("""
+            from airports
+            | where starts_with(first_name, "*Firs") or ends_with(first_name, "irst*")
+            | where ends_with(last_name, "ast")
+            """);
+
+        var optimized = optimizedPlan(plan);
+        var topLimit = as(optimized, LimitExec.class);
+        var exchange = asRemoteExchange(topLimit.child());
+        var project = as(exchange.child(), ProjectExec.class);
+        var fieldExtract = as(project.child(), FieldExtractExec.class);
+        var source = source(fieldExtract.child());
+        assertThat(source.estimatedRowSize(), equalTo(allFieldRowSize + Integer.BYTES));
+
+        var andBool = as(source.query(), BoolQueryBuilder.class);
+        assertThat(andBool.must(), hasSize(2));
+        assertThat(andBool.should(), hasSize(0));
+
+        var orBool = as(andBool.must().get(0), BoolQueryBuilder.class);
+        assertThat(orBool.should(), hasSize(2));
+        assertThat(orBool.must(), hasSize(0));
+
+        var orStartsWith = as(sv(orBool.should().get(0), "first_name"), WildcardQueryBuilder.class);
+        assertThat(orStartsWith.fieldName(), equalTo("first_name"));
+        assertThat(orStartsWith.caseInsensitive(), equalTo(false));
+        assertThat(orStartsWith.value(), equalTo("\\*Firs*"));
+
+        var orEndsWith = as(sv(orBool.should().get(1), "first_name"), WildcardQueryBuilder.class);
+        assertThat(orEndsWith.fieldName(), equalTo("first_name"));
+        assertThat(orEndsWith.caseInsensitive(), equalTo(false));
+        assertThat(orEndsWith.value(), equalTo("*irst\\*"));
+
+        var andEndsWith = as(sv(andBool.must().get(1), "last_name"), WildcardQueryBuilder.class);
+        assertThat(andEndsWith.fieldName(), equalTo("last_name"));
+        assertThat(andEndsWith.caseInsensitive(), equalTo(false));
+        assertThat(andEndsWith.value(), equalTo("*ast"));
+    }
+
     public void testLimit() {
         var optimized = optimizedPlan(physicalPlan("""
             from test