创建一个查看空间的存储过程
create or replace procedure show_space
( p_segname in varchar2,
p_owner in varchar2 default user,
p_type in varchar2 default 'TABLE',
p_partition in varchar2 default NULL )
-- this procedure uses authid current user so it can query DBA_*
-- views using privileges from a ROLE, and so it can be installed
-- once per database, instead of once per user who wanted to use itauthid current_user
as
l_free_blks number;
l_total_blocks number;
l_total_bytes number;
l_unused_blocks number;
l_unused_bytes number;
l_LastUsedExtFileId number;
l_LastUsedExtBlockId number;
l_LAST_USED_BLOCK number;
l_segment_space_mgmt varchar2(255);
l_unformatted_blocks number;
l_unformatted_bytes number;
l_fs1_blocks number; l_fs1_bytes number;
l_fs2_blocks number; l_fs2_bytes number;
l_fs3_blocks number; l_fs3_bytes number;
l_fs4_blocks number; l_fs4_bytes number;
l_full_blocks number; l_full_bytes number;
-- inline procedure to print out numbers nicely formatted
-- with a simple label
procedure p( p_label in varchar2, p_num in number )
is
begin
dbms_output.put_line( rpad(p_label,40,'.') ||
to_char(p_num,'999,999,999,999') );
end;
begin
-- this query is executed dynamically in order to allow this procedure
-- to be created by a user who has access to DBA_SEGMENTS/TABLESPACES
-- via a role as is customary.
-- NOTE: at runtime, the invoker MUST have access to these two
-- views!
-- this query determines if the object is an ASSM object or not
begin
execute immediate
'select ts.segment_space_management
from dba_segments seg, dba_tablespaces ts
where seg.segment_name = :p_segname
and (:p_partition is null or
seg.partition_name = :p_partition)
and seg.owner = :p_owner
and seg.tablespace_name = ts.tablespace_name'
into l_segment_space_mgmt
using p_segname, p_partition, p_partition, p_owner;
exception
when too_many_rows then
dbms_output.put_line
( 'This must be a partitioned table, use p_partition => ');
return;
end;
-- if the object is in an ASSM tablespace, we must use this API
-- call to get space information, otherwise we use the FREE_BLOCKS
-- API for the user-managed segments
if l_segment_space_mgmt = 'AUTO'
then
dbms_space.space_usage
( p_owner, p_segname, p_type, l_unformatted_blocks,
l_unformatted_bytes, l_fs1_blocks, l_fs1_bytes,
l_fs2_blocks, l_fs2_bytes, l_fs3_blocks, l_fs3_bytes,
l_fs4_blocks, l_fs4_bytes, l_full_blocks, l_full_bytes, p_partition);
p( 'Unformatted Blocks ', l_unformatted_blocks );
p( 'FS1 Blocks (0-25) ', l_fs1_blocks );
p( 'FS2 Blocks (25-50) ', l_fs2_blocks );
p( 'FS3 Blocks (50-75) ', l_fs3_blocks );
p( 'FS4 Blocks (75-100)', l_fs4_blocks );
p( 'Full Blocks ', l_full_blocks );
else
dbms_space.free_blocks(
segment_owner => p_owner,
segment_name => p_segname,
segment_type => p_type,
freelist_group_id => 0,
free_blks => l_free_blks);
p( 'Free Blocks', l_free_blks );
end if;
-- and then the unused space API call to get the rest of the
-- information
dbms_space.unused_space
( segment_owner => p_owner,
segment_name => p_segname,
segment_type => p_type,
partition_name => p_partition,
total_blocks => l_total_blocks,
total_bytes => l_total_bytes,
unused_blocks => l_unused_blocks,
unused_bytes => l_unused_bytes,
LAST_USED_EXTENT_FILE_ID => l_LastUsedExtFileId,
LAST_USED_EXTENT_BLOCK_ID => l_LastUsedExtBlockId,
LAST_USED_BLOCK => l_LAST_USED_BLOCK );
p( 'Total Blocks', l_total_blocks );
p( 'Total Bytes', l_total_bytes );
p( 'Total MBytes', trunc(l_total_bytes/1024/1024) );
p( 'Unused Blocks', l_unused_blocks );
p( 'Unused Bytes', l_unused_bytes );
p( 'Last Used Ext FileId', l_LastUsedExtFileId );
p( 'Last Used Ext BlockId', l_LastUsedExtBlockId );
p( 'Last Used Block', l_LAST_USED_BLOCK );
end;
/
执行查看行迁移块的SQL
SQL> @?/rdbms/admin/utlchain.sql
Table created.
创建一个手动段管理方式的表空间
SQL> create tablespace testing_lmt_mssm datafile '/u01/app/oracle/oradata/shujukuai/testing_mssm.dbf' size 1m REUSE autoextend on next 1m extent management local uniform. size 64k segment space management manual;
Tablespace created.
在手动段管理表空间创建一个表
SQL> create table Move_Test (id int,vc varchar2(4000)) tablespace TESTING_LMT_MSSM;
Table created.
SQL> alter table Move_Test add constraint Move_Test_pk primary key(id);
Table altered.
SQL> insert into Move_Test values (1,'a');
1 row created.
SQL> insert into Move_Test values (2,'b');
1 row created.
SQL> insert into Move_Test values (3,'c');
1 row created.
SQL> set serveroutput on;
SQL> exec show_space('MOVE_TEST','SYS','TABLE');
Free Blocks............................. 1
Total Blocks............................ 8
Total Bytes............................. 65,536
Total MBytes............................ 0
Unused Blocks........................... 6
Unused Bytes............................ 49,152
Last Used Ext FileId.................... 10
Last Used Ext BlockId................... 9
Last Used Block......................... 2
PL/SQL procedure successfully completed.
设置当前该表所有块的最大的行数作为块中行数的限制
这个命令是将当前我们块中的最高行数的块作为以后块能插入的上限
SQL> alter table Move_Test minimize records_per_block;
Table altered.
SQL> alter table Move_Test minimize records_per_block;
Table altered.
SQL>
SQL> exec show_space('MOVE_TEST','SYS','TABLE');
Free Blocks............................. 1
Total Blocks............................ 8
Total Bytes............................. 65,536
Total MBytes............................ 0
Unused Blocks........................... 6
Unused Bytes............................ 49,152
Last Used Ext FileId.................... 10
Last Used Ext BlockId................... 9
Last Used Block......................... 2
PL/SQL procedure successfully completed.
SQL> insert into Move_Test values (4,'d');
1 row created.
SQL> exec show_space('MOVE_TEST','SYS','TABLE');
Free Blocks............................. 1
Total Blocks............................ 8
Total Bytes............................. 65,536
Total MBytes............................ 0
Unused Blocks........................... 5
Unused Bytes............................ 40,960
Last Used Ext FileId.................... 10
Last Used Ext BlockId................... 9
Last Used Block......................... 3
PL/SQL procedure successfully completed.
SQL> insert into Move_Test values (5,'e');
1 row created.
SQL> exec show_space('MOVE_TEST','SYS','TABLE');
Free Blocks............................. 1
Total Blocks............................ 8
Total Bytes............................. 65,536
Total MBytes............................ 0
Unused Blocks........................... 5
Unused Bytes............................ 40,960
Last Used Ext FileId.................... 10
Last Used Ext BlockId................... 9
Last Used Block......................... 3
PL/SQL procedure successfully completed.
SQL> insert into Move_Test values (6,'f');
1 row created.
SQL> exec show_space('MOVE_TEST','SYS','TABLE');
Free Blocks............................. 1
Total Blocks............................ 8
Total Bytes............................. 65,536
Total MBytes............................ 0
Unused Blocks........................... 5
Unused Bytes............................ 40,960
Last Used Ext FileId.................... 10
Last Used Ext BlockId................... 9
Last Used Block......................... 3
PL/SQL procedure successfully completed.
SQL> insert into Move_Test values (7,'g');
1 row created.
SQL> exec show_space('MOVE_TEST','SYS','TABLE');
Free Blocks............................. 1
Total Blocks............................ 8
Total Bytes............................. 65,536
Total MBytes............................ 0
Unused Blocks........................... 4
Unused Bytes............................ 32,768
Last Used Ext FileId.................... 10
Last Used Ext BlockId................... 9
Last Used Block......................... 4
PL/SQL procedure successfully completed.
SQL> drop table move_test;
Table dropped.
SQL> create table Move_Test (id int,vc varchar2(4000)) tablespace TESTING_LMT_MSSM;
Table created.
SQL> alter table Move_Test add constraint Move_Test_pk primary key(id);
Table altered.
SQL> insert into Move_Test values (1,'a');
1 row created.
SQL> exec show_space('MOVE_TEST','SYS','TABLE');
Free Blocks............................. 1
Total Blocks............................ 8
Total Bytes............................. 65,536
Total MBytes............................ 0
Unused Blocks........................... 6
Unused Bytes............................ 49,152
Last Used Ext FileId.................... 10
Last Used Ext BlockId................... 17 当前表所在区的最后位置
Last Used Block......................... 2 当前高水位
PL/SQL procedure successfully completed.
SQL> alter table Move_Test minimize records_per_block;
Table altered.
SQL> insert into Move_Test values (2,'b');
1 row created.
SQL> insert into Move_Test values (3,'c');
1 row created.
SQL> exec show_space('MOVE_TEST','SYS','TABLE');
Free Blocks............................. 1
Total Blocks............................ 8
Total Bytes............................. 65,536
Total MBytes............................ 0
Unused Blocks........................... 5
Unused Bytes............................ 40,960
Last Used Ext FileId.................... 10
Last Used Ext BlockId................... 17
Last Used Block......................... 3
PL/SQL procedure successfully completed.
SQL> insert into Move_Test values (4,'d');
1 row created.
SQL> insert into Move_Test values (5,'e');
1 row created.
SQL> commit;
Commit complete.
SQL> insert into Move_Test select 5+rownum ,vc from Move_Test where rownum <=4;
4 rows created.
SQL> exec show_space('MOVE_TEST','SYS','TABLE');
Free Blocks............................. 1
Total Blocks............................ 8
Total Bytes............................. 65,536
Total MBytes............................ 0
Unused Blocks........................... 2
Unused Bytes............................ 16,384
Last Used Ext FileId.................... 10
Last Used Ext BlockId................... 17
Last Used Block......................... 6
PL/SQL procedure successfully completed.
SQL> SELECT dbms_rowid.rowid_block_number(rowid), id FROM Move_Test;
DBMS_ROWID.ROWID_BLOCK_NUMBER(ROWID) ID
------------------------------------ ----------
18 1
18 2
19 3
19 4
20 5
20 6
21 7
21 8
22 9
9 rows selected.
SQL> delete Move_Test where id = 6;
1 row deleted.
SQL> delete Move_Test where id = 7;
1 row deleted.
SQL> exec show_space('MOVE_TEST','SYS','TABLE');
Free Blocks............................. 1
Total Blocks............................ 8
Total Bytes............................. 65,536
Total MBytes............................ 0
Unused Blocks........................... 2
Unused Bytes............................ 16,384
Last Used Ext FileId.................... 10
Last Used Ext BlockId................... 17
Last Used Block......................... 6
PL/SQL procedure successfully completed.
SQL> alter table Move_Test move;
Table altered.
SQL> exec show_space('MOVE_TEST','SYS','TABLE');
Free Blocks............................. 0
Total Blocks............................ 8
Total Bytes............................. 65,536
Total MBytes............................ 0
Unused Blocks........................... 3
Unused Bytes............................ 24,576
Last Used Ext FileId.................... 10
Last Used Ext BlockId................... 25
Last Used Block......................... 5 说明MOVE TABLE可以降低高水位
PL/SQL procedure successfully completed.
SQL> set autot on
SQL> col vc for a20
SQL> select * from Move_Test where id =4;
ID VC
---------- --------------------
4 d
Execution Plan
----------------------------------------------------------
Plan hash value: 3979742538
-------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
-------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 3 | 6045 | 3 (0)| 00:00:01 |
|* 1 | TABLE ACCESS FULL| MOVE_TEST | 3 | 6045 | 3 (0)| 00:00:01 |
-------------------------------------------------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
1 - filter("ID"=4)
Statistics
----------------------------------------------------------
0 recursive calls
0 db block gets
6 consistent gets
0 physical reads
0 redo size
571 bytes sent via SQL*Net to client
492 bytes received via SQL*Net from client
2 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
1 rows processed
SQL> analyze table Move_Test compute statistics for table for all indexes for all indexed columns;
analyze table Move_Test compute statistics for table for all indexes for all indexed columns
*
ERROR at line 1:
ORA-01502: index 'SYS.MOVE_TEST_PK' or partition of such index is in unusable
state
SQL> alter index Move_Test_pk rebuild online;
Index altered.
SQL> select /*+ rule */ * from Move_Test where id =4;
ID VC
---------- --------------------
4 d
Execution Plan
----------------------------------------------------------
Plan hash value: 1236992891
----------------------------------------------------
| Id | Operation | Name |
----------------------------------------------------
| 0 | SELECT STATEMENT | |
| 1 | TABLE ACCESS BY INDEX ROWID| MOVE_TEST |
|* 2 | INDEX UNIQUE SCAN | MOVE_TEST_PK | 说明MOVE表可以降低高水位，可是也导致了索引失效
----------------------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
2 - access("ID"=4)
Note
-----
- rule based optimizer used (consider using cbo)
Statistics
----------------------------------------------------------
15 recursive calls
0 db block gets
5 consistent gets
0 physical reads
0 redo size
571 bytes sent via SQL*Net to client
492 bytes received via SQL*Net from client
2 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
1 rows processed
SQL> set autot off
SQL> select spare1 from user_objects,tab$ where object_name ='MOVE_TEST' and tab$.obj# = user_objects.object_id;
SPARE1
----------
32769 查看表中理论上还可以插入多少行
来自 “ ITPUB博客 ” ，链接：http://blog.itpub.net/21158541/viewspace-668386/，如需转载，请注明出处，否则将追究法律责任。
转载于:http://blog.itpub.net/21158541/viewspace-668386/
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