message: Need to use "offset" here now rather than using row_ids[0]
diff: @@ -221,8 +221,10 @@ void ColumnData::RevertAppend(row_t start_row) {
  }
  void ColumnData::Fetch(ColumnScanState &state, row_t row_id, Vector &result) {
  + D_ASSERT(row_id >= 0);
  + D_ASSERT(idx_t(row_id) >= start);
  // perform the fetch within the segment
  - state.row_index = row_id / STANDARD_VECTOR_SIZE * STANDARD_VECTOR_SIZE;
  + state.row_index = start + ((row_id - start) / STANDARD_VECTOR_SIZE * STANDARD_VECTOR_SIZE);
  state.current = (ColumnSegment *)data.GetSegment(state.row_index);
  ScanVector(state, result);
  }
  @@ -248,7 +250,7 @@ void ColumnData::Update(Transaction &transaction, idx_t column_index, Vector &up
  }
  Vector base_vector(type);
  ColumnScanState state;
  - Fetch(state, row_ids[0], base_vector);
  + Fetch(state, row_ids[offset], base_vector);
  updates->Update(transaction, column_index, update_vector, row_ids, offset, update_count, base_vector);
  }
  