compact ddl sstable later check ddl sstable count

src/storage/ddl/ob_ddl_merge_task.cpp

@@ -772,7 +772,7 @@ int ObTabletDDLUtil::compact_ddl_sstable(const ObTablesHandleArray &ddl_sstables
   ObBlockMetaTree meta_tree;
   ObArray<const ObDataMacroBlockMeta *> sorted_metas;
   bool is_data_complete = false;
-  if (OB_UNLIKELY(!ddl_param.is_valid() || ddl_sstables.empty() || (is_commit && !rec_scn.is_valid_and_not_min()))) {
+  if (OB_UNLIKELY(!ddl_param.is_valid() || (is_commit && !rec_scn.is_valid_and_not_min()))) {
     ret = OB_INVALID_ARGUMENT;
     LOG_WARN("invalid argument", K(ret), K(ddl_param), K(ddl_sstables.get_count()), K(is_commit), K(rec_scn));
   } else if (OB_FAIL(ObTabletDDLUtil::check_data_integrity(ddl_sstables,

src/storage/ddl/ob_tablet_ddl_kv_mgr.cpp

@@ -32,7 +32,7 @@ using namespace oceanbase::storage;
 ObTabletDDLKvMgr::ObTabletDDLKvMgr()
   : is_inited_(false), success_start_scn_(SCN::min_scn()), ls_id_(), tablet_id_(), table_key_(), data_format_version_(0),
     start_scn_(SCN::min_scn()), commit_scn_(SCN::min_scn()), max_freeze_scn_(SCN::min_scn()),
-    table_id_(0), execution_id_(-1), head_(0), tail_(0), lock_(), ref_cnt_(0)
+    table_id_(0), execution_id_(-1), ddl_task_id_(0), head_(0), tail_(0), lock_(), ref_cnt_(0)
 {
 }
 
@@ -66,6 +66,7 @@ void ObTabletDDLKvMgr::destroy()
   max_freeze_scn_.set_min();
   table_id_ = 0;
   execution_id_ = -1;
+  ddl_task_id_ = 0;
   success_start_scn_.set_min();
   is_inited_ = false;
 }
@@ -158,6 +159,7 @@ int ObTabletDDLKvMgr::ddl_start(ObTablet &tablet,
       // save variables under lock
       saved_start_scn = start_scn_;
       saved_snapshot_version = table_key_.get_snapshot_version();
+      commit_scn_ = get_commit_scn_nolock(tablet.get_tablet_meta());
     }
   }
   if (OB_SUCC(ret) && !checkpoint_scn.is_valid_and_not_min()) {
@@ -537,6 +539,7 @@ void ObTabletDDLKvMgr::cleanup_unlock()
   max_freeze_scn_.set_min();
   table_id_ = 0;
   execution_id_ = -1;
+  ddl_task_id_ = 0;
   success_start_scn_.set_min();
 }