Allow EARLIEST/EARLIEST_BY/LATEST/LATEST_BY for STRING columns without specifying maxStringBytes

sql/src/main/java/org/apache/druid/sql/calcite/aggregation/builtin/EarliestLatestAnySqlAggregator.java

@@ -82,7 +82,7 @@ AggregatorFactory createAggregatorFactory(
           String fieldName,
           String timeColumn,
           ColumnType type,
-          int maxStringBytes
+          Integer maxStringBytes
       )
       {
         switch (type.getType()) {
@@ -108,7 +108,7 @@ AggregatorFactory createAggregatorFactory(
           String fieldName,
           String timeColumn,
           ColumnType type,
-          int maxStringBytes
+          Integer maxStringBytes
       )
       {
         switch (type.getType()) {
@@ -134,7 +134,7 @@ AggregatorFactory createAggregatorFactory(
           String fieldName,
           String timeColumn,
           ColumnType type,
-          int maxStringBytes
+          Integer maxStringBytes
       )
       {
         switch (type.getType()) {
@@ -157,7 +157,7 @@ abstract AggregatorFactory createAggregatorFactory(
         String fieldName,
         String timeColumn,
         ColumnType outputType,
-        int maxStringBytes
+        Integer maxStringBytes
     );
   }
 
@@ -236,7 +236,7 @@ public Aggregation toDruidAggregation(
     final AggregatorFactory theAggFactory;
     switch (args.size()) {
       case 1:
-        theAggFactory = aggregatorType.createAggregatorFactory(aggregatorName, fieldName, null, outputType, -1);
+        theAggFactory = aggregatorType.createAggregatorFactory(aggregatorName, fieldName, null, outputType, null);
         break;
       case 2:
         int maxStringBytes;
@@ -327,8 +327,7 @@ private static class EarliestLatestSqlAggFunction extends SqlAggFunction
           EARLIEST_LATEST_ARG0_RETURN_TYPE_INFERENCE,
           InferTypes.RETURN_TYPE,
           OperandTypes.or(
-              OperandTypes.NUMERIC,
-              OperandTypes.BOOLEAN,
+              OperandTypes.ANY,
               OperandTypes.sequence(
                   "'" + aggregatorType.name() + "(expr, maxBytesPerString)'",
                   OperandTypes.ANY,

sql/src/main/java/org/apache/druid/sql/calcite/aggregation/builtin/EarliestLatestBySqlAggregator.java

@@ -128,7 +128,7 @@ public Aggregation toDruidAggregation(
                 rexNodes.get(1)
             ),
             outputType,
-            -1
+            null
         );
         break;
       case 3:

sql/src/test/java/org/apache/druid/sql/calcite/CalciteQueryTest.java

@@ -13957,13 +13957,13 @@ public void testGreatestFunctionForStringWithIsNull()
                         .setVirtualColumns(
                             expressionVirtualColumn(
                                 "v0",
-                                "CAST(greatest(\"dim1\",\"dim2\"), 'DOUBLE')",
-                                ColumnType.DOUBLE
+                                "greatest(\"dim1\",\"dim2\")",
+                                ColumnType.STRING
                             )
                         )
                         .setGranularity(Granularities.ALL)
                         .addDimension(new DefaultDimensionSpec("l1", "_d0", ColumnType.LONG))
-                        .addAggregator(new DoubleLastAggregatorFactory("a0", "v0", null))
+                        .addAggregator(new StringLastAggregatorFactory("a0", "v0", null, 1024))
                         .setPostAggregatorSpecs(ImmutableList.of(
                             expressionPostAgg("p0", "isnull(\"a0\")")
                         ))
@@ -14269,4 +14269,31 @@ public void testFilterWithNVLAndNotIn()
         )
     );
   }
+
+  @Test
+  public void testLatestByOnStringColumnWithoutMaxBytesSpecified()
+  {
+    testQuery(
+        "SELECT dim2,LATEST(dim3),LATEST_BY(dim1, __time) FROM druid.foo where dim2='abc' group by 1",
+        ImmutableList.of(
+            GroupByQuery.builder()
+                .setDataSource(CalciteTests.DATASOURCE1)
+                .setInterval(querySegmentSpec(Filtration.eternity()))
+                .setGranularity(Granularities.ALL)
+                .setVirtualColumns(
+                    expressionVirtualColumn("v0", "'abc'", ColumnType.STRING))
+                .setDimFilter(equality("dim2", "abc", ColumnType.STRING))
+                .setDimensions(
+                    dimensions(new DefaultDimensionSpec("v0", "d0", ColumnType.STRING)))
+                .setAggregatorSpecs(
+                    aggregators(
+                        new StringLastAggregatorFactory("a0", "dim3", "__time", 1024),
+                        new StringLastAggregatorFactory("a1", "dim1", "__time", 1024)))
+                .build()
+
+        ),
+        ImmutableList.of(
+            new Object[] {"abc", useDefault ? "" : null, "def"}
+        ));
+  }
 }