Remove ordinal grouping operator

Author: dnhatn

benchmarks/src/main/java/org/elasticsearch/benchmark/compute/operator/ValuesAggregatorBenchmark.java

@@ -95,8 +95,7 @@ static void selfTest() {
         try {
             for (String groups : ValuesAggregatorBenchmark.class.getField("groups").getAnnotationsByType(Param.class)[0].value()) {
                 for (String dataType : ValuesAggregatorBenchmark.class.getField("dataType").getAnnotationsByType(Param.class)[0].value()) {
-                    run(Integer.parseInt(groups), dataType, 10, 0);
-                    run(Integer.parseInt(groups), dataType, 10, 1);
+                    run(Integer.parseInt(groups), dataType, 10);
                 }
             }
         } catch (NoSuchFieldException e) {
@@ -114,10 +113,7 @@ static void selfTest() {
     @Param({ BYTES_REF, INT, LONG })
     public String dataType;
 
-    @Param({ "0", "1" })
-    public int numOrdinalMerges;
-
-    private static Operator operator(DriverContext driverContext, int groups, String dataType, int numOrdinalMerges) {
+    private static Operator operator(DriverContext driverContext, int groups, String dataType) {
         if (groups == 1) {
             return new AggregationOperator(
                 List.of(supplier(dataType).aggregatorFactory(AggregatorMode.SINGLE, List.of(0)).apply(driverContext)),
@@ -132,20 +128,8 @@ private static Operator operator(DriverContext driverContext, int groups, String
         ) {
             @Override
             public Page getOutput() {
-                mergeOrdinal();
                 return super.getOutput();
             }
-
-            // simulate OrdinalsGroupingOperator
-            void mergeOrdinal() {
-                var merged = supplier(dataType).groupingAggregatorFactory(AggregatorMode.SINGLE, List.of(1)).apply(driverContext);
-                for (int i = 0; i < numOrdinalMerges; i++) {
-                    for (int p = 0; p < groups; p++) {
-                        merged.addIntermediateRow(p, aggregators.getFirst(), p);
-                    }
-                }
-                aggregators.set(0, merged);
-            }
         };
     }
 
@@ -352,12 +336,12 @@ private static Block groupingBlock(int groups) {
 
     @Benchmark
     public void run() {
-        run(groups, dataType, OP_COUNT, numOrdinalMerges);
+        run(groups, dataType, OP_COUNT);
     }
 
-    private static void run(int groups, String dataType, int opCount, int numOrdinalMerges) {
+    private static void run(int groups, String dataType, int opCount) {
         DriverContext driverContext = driverContext();
-        try (Operator operator = operator(driverContext, groups, dataType, numOrdinalMerges)) {
+        try (Operator operator = operator(driverContext, groups, dataType)) {
             Page page = page(groups, dataType);
             for (int i = 0; i < opCount; i++) {
                 operator.addInput(page.shallowCopy());

x-pack/plugin/esql/compute/src/main/java/org/elasticsearch/compute/aggregation/GroupingAggregator.java

@@ -70,13 +70,6 @@ public void close() {}
         }
     }
 
-    /**
-     * Add the position-th row from the intermediate output of the given aggregator to this aggregator at the groupId position
-     */
-    public void addIntermediateRow(int groupId, GroupingAggregator input, int position) {
-        aggregatorFunction.addIntermediateRowInput(groupId, input.aggregatorFunction, position);
-    }
-
     /**
      * Build the results for this aggregation.
      * @param selected the groupIds that have been selected to be included in

x-pack/plugin/esql/compute/src/main/java/org/elasticsearch/compute/aggregation/GroupingAggregatorFunction.java

@@ -130,6 +130,7 @@ default void add(int positionOffset, IntBlock groupIds) {
 
     /**
      * Add the position-th row from the intermediate output of the given aggregator function to the groupId
+     * TODO: Remove this method as the grouping operator has been removed
      */
     void addIntermediateRowInput(int groupId, GroupingAggregatorFunction input, int position);