DB2表空间管理(2)—DMS空间管理篇

db2的DMS表空间管理主要有Exent/Reduce/Resize/Add/begin new stripe set,下面分别对这几项进行介绍
Exent扩展已有容器

[db2inst2@xifenfei ~]$ db2 list tablespace containers for 3 show detail

            Tablespace Containers for Tablespace 3

 Container ID                         = 0
 Name                                 = /home/db2inst2/dms/tbs_data01.dbf
 Type                                 = File
 Total pages                          = 3200
 Useable pages                        = 3168
 Accessible                           = Yes


SQL> select 3200*32/1024 from dual;

3200*32/1024
------------
         100

[db2inst2@xifenfei ~]$ db2 "alter tablespace tbs_data extend (file 
'/home/db2inst2/dms/tbs_data01.dbf' 20M)"
DB20000I  The SQL command completed successfully.
[db2inst2@xifenfei ~]$ db2 list tablespace containers for 3 show detail

            Tablespace Containers for Tablespace 3

 Container ID                         = 0
 Name                                 = /home/db2inst2/dms/tbs_data01.dbf
 Type                                 = File
 Total pages                          = 3840
 Useable pages                        = 3808
 Accessible                           = Yes

SQL> select 3840*32/1024 from dual;

3840*32/1024
------------
         120

Reduce缩减已有容器

[db2inst2@xifenfei ~]$ db2 "alter tablespace tbs_data reduce (file     
'/home/db2inst2/dms/tbs_data01.dbf' 40M)"
DB20000I  The SQL command completed successfully.
[db2inst2@xifenfei ~]$ db2 list tablespace containers for 3 show detail

            Tablespace Containers for Tablespace 3

 Container ID                         = 0
 Name                                 = /home/db2inst2/dms/tbs_data01.dbf
 Type                                 = File
 Total pages                          = 2560
 Useable pages                        = 2528
 Accessible                           = Yes

SQL> select 2560*32/1024 from dual;

2560*32/1024
------------
          80

Resize重设容器大小

[db2inst2@xifenfei ~]$ db2 "alter tablespace tbs_data resize (file     
'/home/db2inst2/dms/tbs_data01.dbf' 30M)"
DB20000I  The SQL command completed successfully.
[db2inst2@xifenfei ~]$ db2 list tablespace containers for 3 show detail

            Tablespace Containers for Tablespace 3

 Container ID                         = 0
 Name                                 = /home/db2inst2/dms/tbs_data01.dbf
 Type                                 = File
 Total pages                          = 960
 Useable pages                        = 928
 Accessible                           = Yes

SQL> select 960*32/1024 from dual;

960*32/1024
-----------
         30

Add增加新容器

[db2inst2@xifenfei ~]$ db2 "alter tablespace tbs_data add (file        
'/home/db2inst2/dms/tbs_data02.dbf' 30M)"
DB20000I  The SQL command completed successfully.
[db2inst2@xifenfei ~]$ db2 list tablespace containers for 3 show detail

            Tablespace Containers for Tablespace 3

 Container ID                         = 0
 Name                                 = /home/db2inst2/dms/tbs_data01.dbf
 Type                                 = File
 Total pages                          = 960
 Useable pages                        = 928
 Accessible                           = Yes
 Container ID                         = 1
 Name                                 = /home/db2inst2/dms/tbs_data02.dbf
 Type                                 = File
 Total pages                          = 960
 Useable pages                        = 928
 Accessible                           = Yes

Add增加新容器后，会在容器件进行数据Rebalance

begin new stripe set增加新容器

[db2inst2@xifenfei ~]$ db2 "alter tablespace tbs_data begin new stripe set (file 
'/home/db2inst2/dms/tbs_data03.dbf' 10M)"
DB20000I  The SQL command completed successfully.
[db2inst2@xifenfei ~]$ db2 list tablespace containers for 3 show detail

            Tablespace Containers for Tablespace 3

 Container ID                         = 0
 Name                                 = /home/db2inst2/dms/tbs_data01.dbf
 Type                                 = File
 Total pages                          = 960
 Useable pages                        = 928
 Accessible                           = Yes
 Container ID                         = 1
 Name                                 = /home/db2inst2/dms/tbs_data02.dbf
 Type                                 = File
 Total pages                          = 960
 Useable pages                        = 928
 Accessible                           = Yes
 Container ID                         = 2
 Name                                 = /home/db2inst2/dms/tbs_data03.dbf
 Type                                 = File
 Total pages                          = 320
 Useable pages                        = 288
 Accessible                           = Yes

begin new stripe set当已有容器使用完之后，再使用新增加容器