[fix](partial update) fix data correctness risk when load delete sign data into a table with sequence col

be/src/olap/rowset/segment_v2/segment_writer.cpp

@@ -533,10 +533,12 @@ Status SegmentWriter::append_block_with_partial_content(const vectorized::Block*
             return st;
         }
 
-        // if the delete sign is marked, it means that the value columns of the row
-        // will not be read. So we don't need to read the missing values from the previous rows.
-        // But we still need to mark the previous row on delete bitmap
-        if (have_delete_sign) {
+        // 1. if the delete sign is marked, it means that the value columns of the row will not
+        //    be read. So we don't need to read the missing values from the previous rows.
+        // 2. the one exception is when there are sequence columns in the table, we need to read
+        //    the sequence columns, otherwise it may cause the merge-on-read based compaction
+        //    policy to produce incorrect results
+        if (have_delete_sign && !_tablet_schema->has_sequence_col()) {
             has_default_or_nullable = true;
             use_default_or_null_flag.emplace_back(true);
         } else {
@@ -722,7 +724,7 @@ Status SegmentWriter::fill_missing_columns(vectorized::MutableColumns& mutable_f
             (delete_sign_column_data != nullptr &&
              delete_sign_column_data[read_index[idx + segment_start_pos]] != 0)) {
             for (auto i = 0; i < cids_missing.size(); ++i) {
-                // if the column has default value, fiil it with default value
+                // if the column has default value, fill it with default value
                 // otherwise, if the column is nullable, fill it with null value
                 const auto& tablet_column = _tablet_schema->column(cids_missing[i]);
                 if (tablet_column.has_default_value()) {

be/src/olap/rowset/segment_v2/vertical_segment_writer.cpp

@@ -464,10 +464,12 @@ Status VerticalSegmentWriter::_append_block_with_partial_content(RowsInBlock& da
             return st;
         }
 
-        // if the delete sign is marked, it means that the value columns of the row
-        // will not be read. So we don't need to read the missing values from the previous rows.
-        // But we still need to mark the previous row on delete bitmap
-        if (have_delete_sign) {
+        // 1. if the delete sign is marked, it means that the value columns of the row will not
+        //    be read. So we don't need to read the missing values from the previous rows.
+        // 2. the one exception is when there are sequence columns in the table, we need to read
+        //    the sequence columns, otherwise it may cause the merge-on-read based compaction
+        //    policy to produce incorrect results
+        if (have_delete_sign && !_tablet_schema->has_sequence_col()) {
             has_default_or_nullable = true;
             use_default_or_null_flag.emplace_back(true);
         } else {
@@ -648,7 +650,7 @@ Status VerticalSegmentWriter::_fill_missing_columns(
             (delete_sign_column_data != nullptr &&
              delete_sign_column_data[read_index[idx + segment_start_pos]] != 0)) {
             for (auto i = 0; i < missing_cids.size(); ++i) {
-                // if the column has default value, fiil it with default value
+                // if the column has default value, fill it with default value
                 // otherwise, if the column is nullable, fill it with null value
                 const auto& tablet_column = _tablet_schema->column(missing_cids[i]);
                 if (tablet_column.has_default_value()) {

regression-test/suites/unique_with_mow_p0/partial_update/test_partial_update_seq_col_delete.groovy

@@ -80,6 +80,14 @@ suite("test_primary_key_partial_update_seq_col_delete", "p0") {
                 select * from ${tableName} order by id;
             """
 
+            sql "SET show_hidden_columns=true"
+
+            sql "sync"
+            qt_partial_update_without_seq_hidden_columns """
+                select * from ${tableName} order by id;
+            """
+
+            sql "SET show_hidden_columns=false"
             // provide the sequence column this time, should update according to the
             // given sequence values
             streamLoad {