（五）增加lob列和普通列，查看空间变化【达梦dba_segments指定表名查询到的大小都包含哪些数据】alter table test01 add content clob;SQL> select owner,segment_name,bytes,blocks,extents,initial_extent from dba_segments where owner='SYSDBA' and segment_name='TEST01';OWNER SEGMENT_NAME BYTES BLOCKS EXTENTS INITIAL_EXTENT------ ------------ -------------------- -------------------- -------------------- --------------------SYSDBA TEST01 8388608 256 8 1048576alter table test01 add city varchar2(10);SQL> select owner,segment_name,bytes,blocks,extents,initial_extent from dba_segments where owner='SYSDBA' and segment_name='TEST01';OWNER SEGMENT_NAME BYTES BLOCKS EXTENTS INITIAL_EXTENT------ ------------ -------------------- -------------------- -------------------- --------------------SYSDBA TEST01 8388608 256 8 1048576SQL> select id,name,crtdate from sysobjects where name='TEST01' and schid in(select id from sysobjects where name='SYSDBA' and type$='SCH');ID NAME CRTDATE----------- ------ --------------------------5751 TEST01 2022-02-22 14:55:03.347000SQL> SELECT TABLE_USED_LOB_PAGES('SYSDBA','TEST01');TABLE_USED_LOB_PAGES('SYSDBA','TEST01')---------------------------------------6 ---这个返回的是数据块，2个簇实际在用的数据块数量只有6个（六）创建包含LOB字段的表SQL> create table test02(id number,name varchar2(10),content clob);SQL> select owner,segment_name,bytes,blocks,extents,initial_extent from dba_segments where owner='SYSDBA' and segment_name='TEST02';OWNER SEGMENT_NAME BYTES BLOCKS EXTENTS INITIAL_EXTENT------ ------------ -------------------- -------------------- -------------------- --------------------SYSDBA TEST02 4194304 128 4 1048576
