diff --git a/src/storage/compaction/ob_medium_compaction_func.cpp b/src/storage/compaction/ob_medium_compaction_func.cpp
index c4257669f..19711ef8a 100644
--- a/src/storage/compaction/ob_medium_compaction_func.cpp
+++ b/src/storage/compaction/ob_medium_compaction_func.cpp
@@ -726,8 +726,21 @@ int ObMediumCompactionScheduleFunc::check_if_schema_changed(
     bool &is_schema_changed)
 {
   int ret = OB_SUCCESS;
+  is_schema_changed = false;
   int64_t full_stored_col_cnt = 0;
-  if (OB_UNLIKELY(!schema.is_inited())) {
+  ObTabletMemberWrapper<ObTabletTableStore> wrapper;
+  ObSSTable *last_major = nullptr;
+
+  if (OB_FAIL(tablet.fetch_table_store(wrapper))) {
+    LOG_WARN("failed to get table store wrapper", K(ret));
+  } else if (FALSE_IT(last_major = static_cast<ObSSTable*>(wrapper.get_member()->get_major_sstables().get_boundary_table(true/*last*/)))) {
+  } else if (OB_ISNULL(last_major)) {
+    ret = OB_ERR_UNEXPECTED;
+    LOG_WARN("get unexpected null major sstable", KR(ret), KPC(last_major));
+  } else if (0 == last_major->get_data_macro_block_count()
+          && ObCompressorType::NONE_COMPRESSOR == tablet.get_last_major_compressor_type()) {
+    // empty major, no need to check whether schema changed
+  } else if (OB_UNLIKELY(!schema.is_inited())) {
     ret = OB_ERR_UNEXPECTED;
     LOG_WARN("schema is not inited", KR(ret), K(schema));
   } else if (OB_FAIL(schema.get_stored_column_count_in_sstable(full_stored_col_cnt))) {
@@ -735,19 +748,23 @@ int ObMediumCompactionScheduleFunc::check_if_schema_changed(
   } else if (OB_UNLIKELY(tablet.get_last_major_column_count() > full_stored_col_cnt)) {
     ret = OB_ERR_UNEXPECTED;
     LOG_ERROR("stored col cnt in curr schema is less than old major sstable", K(ret),
-      "col_cnt_in_sstable", tablet.get_last_major_column_count(),
-      "col_cnt_in_schema", full_stored_col_cnt, K(schema));
-  } else if (tablet.get_last_major_column_count() != full_stored_col_cnt
-    || tablet.get_last_major_compressor_type() != schema.get_compressor_type()
-    || (ObRowStoreType::DUMMY_ROW_STORE != tablet.get_last_major_latest_row_store_type()
-      && tablet.get_last_major_latest_row_store_type() != schema.row_store_type_)) {
+              "col_cnt_in_sstable", tablet.get_last_major_column_count(),
+              "col_cnt_in_schema", full_stored_col_cnt, K(schema));
+  } else if (tablet.get_last_major_column_count() != full_stored_col_cnt) {
     is_schema_changed = true;
     LOG_INFO("schema changed", K(schema), K(full_stored_col_cnt),
-             "col_cnt_in_sstable", tablet.get_last_major_column_count(),
-             "compressor_type_in_sstable", tablet.get_last_major_compressor_type(),
+             "col_cnt_in_sstable", tablet.get_last_major_column_count());
+  } else if (ObRowStoreType::DUMMY_ROW_STORE != tablet.get_last_major_latest_row_store_type()
+          && tablet.get_last_major_latest_row_store_type() != schema.row_store_type_) {
+    is_schema_changed = true;
+    LOG_INFO("schema changed", K(schema),
              "latest_row_store_type_in_sstable", tablet.get_last_major_latest_row_store_type());
+  } else if (tablet.get_last_major_compressor_type() == schema.get_compressor_type()) {
+    // schema not changed, do nothing
   } else {
-    is_schema_changed = false;
+    is_schema_changed = true;
+    LOG_INFO("schema changed", K(schema), KPC(last_major),
+             "compressor_type_in_sstable", tablet.get_last_major_compressor_type());
   }
   return ret;
 }
diff --git a/src/storage/tablet/ob_tablet.cpp b/src/storage/tablet/ob_tablet.cpp
index 405f61921..6a1df6609 100644
--- a/src/storage/tablet/ob_tablet.cpp
+++ b/src/storage/tablet/ob_tablet.cpp
@@ -95,6 +95,7 @@
 #include "share/ob_tablet_replica_checksum_operator.h"
 #include "storage/blocksstable/ob_datum_row_utils.h"
 #include "storage/compaction/ob_partition_merge_policy.h"
+#include "observer/ob_server_event_history_table_operator.h"
 
 namespace oceanbase
 {
@@ -5615,6 +5616,9 @@ int ObTablet::build_migration_tablet_param_major_ckm_info(
       LOG_WARN("major ckm info on table store is invalid", K(ret), K(tablet_id), K(major_ckm_info));
     } else if (major_ckm_info.is_empty() || is_output_exec_mode(major_ckm_info.get_exec_mode())) {
       // do not copy OUTPUT major ckm info to migrate or backup
+#ifdef ERRSIM
+      SERVER_EVENT_SYNC_ADD("ss_merge_errsim", "src_is_exec_svr", "tenant_id", MTL_ID(), "ls_id", tablet_meta_.get_ls_id());
+#endif
     } else if (OB_FAIL(mig_tablet_param.major_ckm_info_.assign(major_ckm_info, &mig_tablet_param.allocator_))) {
       LOG_WARN("failed to assign major ckm info from table store", K(ret), K(tablet_id), K(table_store));
     }