mariadb-server/sql/sql_select.cc:24654:10: warning: destination for this 'memset' call is a pointer to class containing a dynamic class 'Duplicate_weedout_picker'; vtable pointer will be overwritten

      [-Wdynamic-class-memaccess]

  memset(best_positions, 0, sizeof(POSITION) * (table_count + 1));

mariadb-server/sql/sql_select.cc:24654:10: note: explicitly cast the pointer to silence this warning

  memset(best_positions, 0, sizeof(POSITION) * (table_count + 1));

mariadb-server/sql/opt_subselect.cc:2246:21: warning: destination for this 'memcpy' call is a pointer to class containing a dynamic class 'Duplicate_weedout_picker'; vtable pointer will be overwritten

      [-Wdynamic-class-memaccess]

        memcpy(sjm->positions, join->best_positions + join->const_tables, 

mariadb-server/sql/opt_subselect.cc:2246:21: note: explicitly cast the pointer to silence this warning

        memcpy(sjm->positions, join->best_positions + join->const_tables, 

mariadb-server/sql/opt_subselect.cc:3350:32: warning: destination for this 'memcpy' call is a pointer to class containing a dynamic class 'Duplicate_weedout_picker'; vtable pointer will be overwritten

      [-Wdynamic-class-memaccess]

      memcpy(pos - sjm->tables + 1, sjm->positions, 

mariadb-server/sql/opt_subselect.cc:3350:32: note: explicitly cast the pointer to silence this warning

      memcpy(pos - sjm->tables + 1, sjm->positions, 

mariadb-server/sql/opt_subselect.cc:3366:35: warning: destination for this 'memcpy' call is a pointer to class containing a dynamic class 'Duplicate_weedout_picker'; vtable pointer will be overwritten

      [-Wdynamic-class-memaccess]

      memcpy(join->best_positions + first, 

mariadb-server/sql/opt_subselect.cc:3366:35: note: explicitly cast the pointer to silence this warning

      memcpy(join->best_positions + first,