#KYLIN-4158, limit not push down to storage scan level if group by is…

… an expression

core-storage/src/main/java/org/apache/kylin/storage/gtrecord/GTCubeStorageQueryBase.java

@@ -103,7 +103,8 @@ public ITupleIterator search(StorageContext context, SQLDigest sqlDigest, TupleI
             return ITupleIterator.EMPTY_TUPLE_ITERATOR;
 
         return new SequentialCubeTupleIterator(scanners, request.getCuboid(), request.getDimensions(),
-                request.getDynGroups(), request.getGroups(), request.getMetrics(), returnTupleInfo, request.getContext(), sqlDigest);
+                request.getDynGroups(), request.getGroups(), request.getMetrics(), returnTupleInfo,
+                request.getContext(), sqlDigest);
     }
 
     public GTCubeStorageQueryRequest getStorageQueryRequest(StorageContext context, SQLDigest sqlDigest,
@@ -177,7 +178,7 @@ public GTCubeStorageQueryRequest getStorageQueryRequest(StorageContext context,
 
         // set limit push down
         enableStorageLimitIfPossible(cuboid, groups, dynGroups, derivedPostAggregation, groupsD, filterD,
-                loosenedColumnD, sqlDigest.aggregations, context);
+                loosenedColumnD, sqlDigest, context);
         // set whether to aggregate results from multiple partitions
         enableStreamAggregateIfBeneficial(cuboid, groupsD, context);
         // check query deadline
@@ -421,7 +422,8 @@ private void collectColumnsRecursively(TupleFilter filter, Set<TblColRef> collec
 
     private void enableStorageLimitIfPossible(Cuboid cuboid, Collection<TblColRef> groups, List<TblColRef> dynGroups,
             Set<TblColRef> derivedPostAggregation, Collection<TblColRef> groupsD, TupleFilter filter,
-            Set<TblColRef> loosenedColumnD, Collection<FunctionDesc> functionDescs, StorageContext context) {
+            Set<TblColRef> loosenedColumnD, SQLDigest sqlDigest, StorageContext context) {
+        Collection<FunctionDesc> functionDescs = sqlDigest.aggregations;
 
         StorageLimitLevel storageLimitLevel = StorageLimitLevel.LIMIT_ON_SCAN;
 
@@ -469,6 +471,11 @@ private void enableStorageLimitIfPossible(Cuboid cuboid, Collection<TblColRef> g
             }
         }
 
+        if (sqlDigest.groupByExpression) {
+            storageLimitLevel = StorageLimitLevel.NO_LIMIT;
+            logger.debug("storageLimitLevel set to NO_LIMIT because group by clause is an expression");
+        }
+
         context.applyLimitPushDown(cubeInstance, storageLimitLevel);
     }
 

kylin-it/src/test/resources/query/sql_casewhen/query57.sql

@@ -0,0 +1,23 @@
+--
+-- Licensed to the Apache Software Foundation (ASF) under one
+-- or more contributor license agreements.  See the NOTICE file
+-- distributed with this work for additional information
+-- regarding copyright ownership.  The ASF licenses this file
+-- to you under the Apache License, Version 2.0 (the
+-- "License"); you may not use this file except in compliance
+-- with the License.  You may obtain a copy of the License at
+--
+--     http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing, software
+-- distributed under the License is distributed on an "AS IS" BASIS,
+-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+-- See the License for the specific language governing permissions and
+-- limitations under the License.
+--
+
+SELECT (CASE WHEN ("TEST_KYLIN_FACT"."LSTG_FORMAT_NAME" IN ('Auction', 'FP-GTC')) THEN 'Auction' ELSE "TEST_KYLIN_FACT"."LSTG_FORMAT_NAME" END) AS "LSTG_FORMAT_NAME__group_",
+  SUM("TEST_KYLIN_FACT"."PRICE") AS "sum_PRICE_ok"
+FROM "TEST_KYLIN_FACT" "TEST_KYLIN_FACT"
+GROUP BY (CASE WHEN ("TEST_KYLIN_FACT"."LSTG_FORMAT_NAME" IN ('Auction', 'FP-GTC')) THEN 'Auction' ELSE "TEST_KYLIN_FACT"."LSTG_FORMAT_NAME" END)
+LIMIT 4