fix schema change

be/src/olap/schema_change.cpp

@@ -866,6 +866,7 @@ Status SchemaChangeJob::_do_process_alter_tablet(const TAlterTabletReqV2& reques
     for (int i = 0; i < num_cols; ++i) {
         return_columns[i] = i;
     }
+    std::vector<uint32_t> cluster_key_idxes;
 
     // begin to find deltas to convert from base tablet to new tablet so that
     // obtain base tablet and new tablet's push lock and header write lock to prevent loading data
@@ -980,6 +981,14 @@ Status SchemaChangeJob::_do_process_alter_tablet(const TAlterTabletReqV2& reques
             reader_context.batch_size = ALTER_TABLE_BATCH_SIZE;
             reader_context.delete_bitmap = &_base_tablet->tablet_meta()->delete_bitmap();
             reader_context.version = Version(0, end_version);
+            if (!_base_tablet_schema->cluster_key_uids().empty()) {
+                for (const auto& uid : _base_tablet_schema->cluster_key_uids()) {
+                    cluster_key_idxes.emplace_back(_base_tablet_schema->field_index(uid));
+                }
+                reader_context.read_orderby_key_columns = &cluster_key_idxes;
+                reader_context.is_unique = false;
+                reader_context.sequence_id_idx = -1;
+            }
             for (auto& rs_split : rs_splits) {
                 res = rs_split.rs_reader->init(&reader_context);
                 if (!res) {
@@ -1366,15 +1375,8 @@ Status SchemaChangeJob::parse_request(const SchemaChangeParams& sc_params,
 
     if (sc_params.enable_unique_key_merge_on_write &&
         new_tablet_schema->num_key_columns() > base_tablet_schema->num_key_columns()) {
-        if (base_tablet_schema->cluster_key_uids().empty()) {
-            *sc_directly = true;
-            return Status::OK();
-        } else {
-            // For mow table with cluster keys, the data in segments of one rowset is sorted by
-            // cluster keys, the short key index may be overlapped.
-            *sc_sorting = true;
-            return Status::OK();
-        }
+        *sc_directly = true;
+        return Status::OK();
     }
 
     if (base_tablet_schema->num_short_key_columns() != new_tablet_schema->num_short_key_columns()) {

regression-test/data/unique_with_mow_c_p0/test_schema_change_add_key_column.out

@@ -1,4 +1,19 @@
 -- This file is automatically generated. You should know what you did if you want to edit this
--- !sql --
+-- !select1 --
 12345	23083	\N	30920	40410
 
+-- !select2 --
+17320	24209	\N	30795	40000
+
+-- !select3 --
+59832	36673	\N	30343	40299
+
+-- !select1 --
+12345	23083	\N	30920	40410
+
+-- !select2 --
+17320	24209	\N	30795	40000
+
+-- !select3 --
+59832	36673	\N	30586	40739
+