oracle自动段管理ASSM笔记

CREATE TABLESPACE demo

DATAFILE ‘J:\app\wufan\oradata\orcl\demo01.dbf‘

SIZE 50M

EXTENT MANAGEMENT LOCAL          --一定是本地管理

SEGMENT SPACE MANAGEMENT AUTO;   --ASSM管理的标志

CREATE TABLE demotab (x NUMBER)

TABLESPACE demo

STORAGE (INITIAL 1000 K);

SQL> show user

USER is "SCOTT"

SQL> SELECT t.table_name,

2         t.initial_extent,

3         t.next_extent,

4         t.pct_free,

5         t.pct_used

6    FROM user_tables t

7   WHERE   t.table_name = ‘DEMOTAB‘;

TABLE_NAME                     INITIAL_EXTENT NEXT_EXTENT   PCT_FREE   PCT_USED

------------------------------ -------------- ----------- ---------- ----------

DEMOTAB                               1024000                     10

SQL> set serveroutput on

SQL> exec scott.show_space(‘demotab‘,‘auto‘,‘T‘,‘Y‘);

Total Blocks............................0

Total Bytes.............................0

Unused Blocks...........................0

Unused Bytes............................0

Last Used Ext FileId....................0

Last Used Ext BlockId...................0

Last Used Block.........................0

*************************************************

The segment is analyzed

0% -- 25% free space blocks.............0

0% -- 25% free space bytes..............0

25% -- 50% free space blocks............0

25% -- 50% free space bytes.............0

50% -- 75% free space blocks............0

50% -- 75% free space bytes.............0

75% -- 100% free space blocks...........0

75% -- 100% free space bytes............0

Unused Blocks...........................0

Unused Bytes............................0

Total Blocks............................0

Total bytes.............................0

PL/SQL procedure successfully completed.

SQL> SELECT   t.segment_name, t.extent_id, t.block_id

2    FROM   dba_extents t

3   WHERE   t.segment_name = ‘DEMOTAB‘;

no rows selected

SQL>

该实验刚好佐证了11g创建一个表，只是产生了一个表定义，并未分配任何空间

附show_space过程代码，觉得这段代码挺有用，记下来mark 一下：

CREATE OR REPLACE PROCEDURE show_space (p_segname_1 IN varchar2,

                                        p_space IN varchar2 DEFAULT 'MANUAL' ,

                                        p_type_1 IN varchar2 DEFAULT 'TABLE' ,

                                        p_analyzed IN varchar2 DEFAULT 'N' ,

                                        p_owner_1 IN varchar2 DEFAULT USER

)

AS

   p_segname              VARCHAR2 (100);

   p_type                 VARCHAR2 (10);

   p_owner                VARCHAR2 (30);

   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;

   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;

   PROCEDURE p (p_label IN varchar2, p_num IN number)

   IS

   BEGIN

      DBMS_OUTPUT.put_line (RPAD (p_label, 40, '.') || p_num);

   END;

BEGIN

   p_segname                 := UPPER (p_segname_1);          -- rainy changed

   p_owner                   := UPPER (p_owner_1);

   p_type                    := p_type_1;

   IF (p_type_1 = 'i' OR p_type_1 = 'I')

   THEN                                                        --rainy changed

      p_type   := 'INDEX';

   END IF;

   IF (p_type_1 = 't' OR p_type_1 = 'T')

   THEN                                                        --rainy changed

      p_type   := 'TABLE';

   END IF;

   IF (p_type_1 = 'c' OR p_type_1 = 'C')

   THEN                                                        --rainy changed

      p_type   := 'CLUSTER';

   END IF;

   DBMS_SPACE.unused_space (segment_owner => p_owner,

                            segment_name => p_segname,

                            segment_type => p_type,

                            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

   );

   IF p_space = 'MANUAL' OR (p_space <> 'auto' AND p_space <> 'AUTO')

   THEN

      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;

   p ('Total Blocks', l_total_blocks);

   p ('Total Bytes', l_total_bytes);

   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);

   /*IF the segment is analyzed */

   IF p_analyzed = 'Y'

   THEN

      DBMS_SPACE.space_usage (segment_owner => p_owner,

                              segment_name => p_segname,

                              segment_type => p_type,

                              unformatted_blocks => l_unformatted_blocks,

                              unformatted_bytes => l_unformatted_bytes,

                              fs1_blocks => l_fs1_blocks,

                              fs1_bytes => l_fs1_bytes,

                              fs2_blocks => l_fs2_blocks,

                              fs2_bytes => l_fs2_bytes,

                              fs3_blocks => l_fs3_blocks,

                              fs3_bytes => l_fs3_bytes,

                              fs4_blocks => l_fs4_blocks,

                              fs4_bytes => l_fs4_bytes,

                              full_blocks => l_full_blocks,

                              full_bytes => l_full_bytes

      );

      DBMS_OUTPUT.put_line (RPAD (' ', 50, '*'));

      DBMS_OUTPUT.put_line ('The segment is analyzed');

      p ('0% -- 25% free space blocks', l_fs1_blocks);

      p ('0% -- 25% free space bytes', l_fs1_bytes);

      p ('25% -- 50% free space blocks', l_fs2_blocks);

      p ('25% -- 50% free space bytes', l_fs2_bytes);

      p ('50% -- 75% free space blocks', l_fs3_blocks);

      p ('50% -- 75% free space bytes', l_fs3_bytes);

      p ('75% -- 100% free space blocks', l_fs4_blocks);

      p ('75% -- 100% free space bytes', l_fs4_bytes);

      p ('Unused Blocks', l_unformatted_blocks);

      p ('Unused Bytes', l_unformatted_bytes);

      p ('Total Blocks', l_full_blocks);

      p ('Total bytes', l_full_bytes);

   END IF;

END;