ignite-sprint-3 - map query sort limit fix (IGNITE-682)

modules/indexing/src/main/java/org/apache/ignite/internal/processors/query/h2/sql/GridSqlQuerySplitter.java

@@ -77,8 +77,10 @@ public static GridCacheTwoStepQuery split(JdbcPreparedStatement stmt, Object[] p
 
         Set<String> colNames = new HashSet<>();
 
+        boolean aggregateFound = false;
+
         for (int i = 0, len = mapExps.size(); i < len; i++) // Remember len because mapExps list can grow.
-            splitSelectExpression(mapExps, rdcExps, colNames, i);
+            aggregateFound |= splitSelectExpression(mapExps, rdcExps, colNames, i);
 
         // Fill select expressions.
         mapQry.clearSelect();
@@ -110,15 +112,20 @@ public static GridCacheTwoStepQuery split(JdbcPreparedStatement stmt, Object[] p
 
         // -- ORDER BY
         if (!srcQry.sort().isEmpty()) {
-            mapQry.clearSort();
+            if (aggregateFound) // Ordering over aggregates does not make sense.
+                mapQry.clearSort(); // Otherwise map sort will be used by offset-limit.
 
             for (GridSqlSortColumn sortCol : srcQry.sort().values())
                 rdcQry.addSort(column(((GridSqlAlias)mapExps.get(sortCol.column())).alias()), sortCol);
         }
 
         // -- LIMIT
-        if (srcQry.limit() != null)
+        if (srcQry.limit() != null) {
+            if (aggregateFound)
+                mapQry.limit(null);
+
             rdcQry.limit(srcQry.limit());
+        }
 
         // -- OFFSET
         if (srcQry.offset() != null) {
@@ -209,19 +216,24 @@ else if (el instanceof GridSqlSubquery)
      * @param rdcSelect Selects for reduce query.
      * @param colNames Set of unique top level column names.
      * @param idx Index.
+     * @return {@code true} If aggregate was found.
      */
-    private static void splitSelectExpression(List<GridSqlElement> mapSelect, GridSqlElement[] rdcSelect,
+    private static boolean splitSelectExpression(List<GridSqlElement> mapSelect, GridSqlElement[] rdcSelect,
         Set<String> colNames, int idx) {
         GridSqlElement el = mapSelect.get(idx);
 
         GridSqlAlias alias = null;
 
+        boolean aggregateFound = false;
+
         if (el instanceof GridSqlAlias) { // Unwrap from alias.
             alias = (GridSqlAlias)el;
             el = alias.child();
         }
 
         if (el instanceof GridSqlAggregateFunction) {
+            aggregateFound = true;
+
             GridSqlAggregateFunction agg = (GridSqlAggregateFunction)el;
 
             GridSqlElement mapAgg, rdcAgg;
@@ -322,6 +334,8 @@ private static void splitSelectExpression(List<GridSqlElement> mapSelect, GridSq
                 rdcSelect[idx] = rdcEl;
             }
         }
+
+        return aggregateFound;
     }
 
     /**