oracle查询对象（表、索引）空间信息

对象的空间分配与空间利用情况，除了从各个方面的分析，如分析表，查询rowid等方法外，其实oracle提供了一个查询空间的包dbms_space，如果我们稍封装一下，将是非常好用的一个东西。

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 it. 
AUTHID 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; else 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;

执行结果将如下所示：

SQL> exec show_space2('test_stevie');
Free Blocks.............................               3
Total Blocks............................              32
Total Bytes.............................         262,144
Total MBytes............................               0
Unused Blocks...........................               0
Unused Bytes............................               0
Last Used Ext FileId....................              27
Last Used Ext BlockId...................          41,617
Last Used Block.........................               8

PL/SQL procedure successfully completed