[ES|QL] Use describe method to generate OrdinalGroupingOperator profile message (#113150) (#113279)

* Use describe method to generate aggregators string

* Improve message

* remove incorrect query change

Author: drewdaemon

x-pack/plugin/esql/compute/src/main/java/org/elasticsearch/compute/operator/OrdinalsGroupingOperator.java

@@ -46,6 +46,7 @@
 import java.util.Objects;
 import java.util.function.IntFunction;
 import java.util.function.Supplier;
+import java.util.stream.Collectors;
 
 import static java.util.Objects.requireNonNull;
 import static java.util.stream.Collectors.joining;
@@ -325,7 +326,11 @@ private static void checkState(boolean condition, String msg) {
 
     @Override
     public String toString() {
-        return this.getClass().getSimpleName() + "[" + "aggregators=" + aggregatorFactories + "]";
+        String aggregatorDescriptions = aggregatorFactories.stream()
+            .map(factory -> "\"" + factory.describe() + "\"")
+            .collect(Collectors.joining(", "));
+
+        return this.getClass().getSimpleName() + "[" + "aggregators=[" + aggregatorDescriptions + "]]";
     }
 
     record SegmentID(int shardIndex, int segmentIndex) {

x-pack/plugin/esql/qa/server/single-node/src/javaRestTest/java/org/elasticsearch/xpack/esql/qa/single_node/RestEsqlIT.java

@@ -323,6 +323,35 @@ public void testProfile() throws IOException {
         );
     }
 
+    public void testProfileOrdinalsGroupingOperator() throws IOException {
+        indexTimestampData(1);
+
+        RequestObjectBuilder builder = requestObjectBuilder().query(fromIndex() + " | STATS AVG(value) BY test.keyword");
+        builder.profile(true);
+        if (Build.current().isSnapshot()) {
+            // Lock to shard level partitioning, so we get consistent profile output
+            builder.pragmas(Settings.builder().put("data_partitioning", "shard").build());
+        }
+        Map<String, Object> result = runEsql(builder);
+
+        List<List<String>> signatures = new ArrayList<>();
+        @SuppressWarnings("unchecked")
+        List<Map<String, Object>> profiles = (List<Map<String, Object>>) ((Map<String, Object>) result.get("profile")).get("drivers");
+        for (Map<String, Object> p : profiles) {
+            fixTypesOnProfile(p);
+            assertThat(p, commonProfile());
+            List<String> sig = new ArrayList<>();
+            @SuppressWarnings("unchecked")
+            List<Map<String, Object>> operators = (List<Map<String, Object>>) p.get("operators");
+            for (Map<String, Object> o : operators) {
+                sig.add((String) o.get("operator"));
+            }
+            signatures.add(sig);
+        }
+
+        assertThat(signatures.get(0).get(2), equalTo("OrdinalsGroupingOperator[aggregators=[\"sum of longs\", \"count\"]]"));
+    }
+
     public void testInlineStatsProfile() throws IOException {
         assumeTrue("INLINESTATS only available on snapshots", Build.current().isSnapshot());
         indexTimestampData(1);