很多人都知道在建立含有lob字段的表时，Oracle会自动为lob字段建立两个单独的segment,一个用来存放数据，另一个用来存放索引，并且它们都会存储在对应表指定的表空间中。但是当我们用alter table tb_name move tablespace tbs_name;来对表做空间迁移时只能移动非lob字段以外的数据，而如果需要同时移动lob相关字段的数据，就必需用如下的含有特殊参数据的语句来完成。
alter table tb_name move tablespace tbs_name
lob (col_lob1,col_lob2) store as(tablesapce tbs_name);
下面是一个具体的示例：
Connected to Oracle8i Enterprise Edition Release 8.1.7.0.0
Connected as scott
SQL> desc test_blob;
Name Type Nullable Default Comments
--------- ------------ -------- ------- --------
FILE_NAME VARCHAR2(25) Y
FILE_BIN BLOB Y
FILE_BIN2 BLOB Y
SQL>
SQL> select t.segment_name, t.segment_type, t.tablespace_name
2 from sys.user_segments t
3 where t.segment_name like 'SYS_%'
4 /
SEGMENT_NAME SEGMENT_TYPE TABLESPACE_NAME
------------------------ - ---------------- --------------
SYS_IL0000025842C00003$$ LOBINDEX SYSTEM
SYS_IL0000025842C00002$$ LOBINDEX SYSTEM
SYS_LOB0000025842C00002$$ LOBSEGMENT SYSTEM
SYS_LOB0000025842C00003$$ LOBSEGMENT SYSTEM
6 rows selected
SQL> alter table test_blob move tablespace tools;
Table altered
SQL>
SQL> select t.segment_name, t.segment_type, t.tablespace_name
2 from sys.user_segments t
3 where t.segment_name like 'SYS_%'
4 /
SEGMENT_NAME SEGMENT_TYPE TABLESPACE_NAME
------------------------- ---------------- --------------
SYS_IL0000025842C00003$$ LOBINDEX SYSTEM
SYS_IL0000025842C00002$$ LOBINDEX SYSTEM
SYS_LOB0000025842C00002$$ LOBSEGMENT SYSTEM
SYS_LOB0000025842C00003$$ LOBSEGMENT SYSTEM
6 rows selected
SQL> select t.segment_name, t.segment_type, t.tablespace_name
2 from sys.user_segments t
3 where t.segment_name like 'TEST_BLOB';
SEGMENT_NAME SEGMENT_TYPE TABLESPACE_NAME
------------------------ ------------- -----------------
TEST_BLOB TABLE TOOLS
SQL> alter table test_blob move tablespace SYSTEM;
Table altered
SQL> ALTER TABLE test_blob MOVE
2 TABLESPACE tools
3 LOB (FILE_BIN,FILE_BIN2) STORE AS
4 (TABLESPACE tools);
Table altered
SQL> select t.segment_name, t.segment_type, t.tablespace_name
2 from sys.user_segments t
3 where t.segment_name like 'SYS_%';
SEGMENT_NAME SEGMENT_TYPE TABLESPACE_NAME
--------------------------- ------------------ ------------------------
SYS_IL0000025842C00003$$ LOBINDEX TOOLS
SYS_IL0000025842C00002$$ LOBINDEX TOOLS
SYS_LOB0000025842C00002$$ LOBSEGMENT TOOLS
SYS_LOB0000025842C00003$$ LOBSEGMENT TOOLS
6 rows selected
本文转自 jxwpx 51CTO博客，原文链接：http://blog.51cto.com/jxwpx/194002，如需转载请自行联系原作者
