学习show_space存储过程

今天学习和介绍一个有用的工具，来自TOM大神的show_space，其实这就是一个存储过程，用他可以统计一些段的用度，非常方便，网上流传着不同的版本。

首先我们看下原版的脚本，https://asktom.oracle.com/pls/apex/f?p=100:11:0::::P11_QUESTION_ID:5350053031470

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 )  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;  procedure p( p_label in varchar2, p_num in number )  is  begin  dbms_output.put_line( rpad(p_label,40,'.') ||  p_num );  end;  begin  for x in ( select tablespace_name  from dba_tablespaces  where tablespace_name = ( select tablespace_name  from dba_segments  where segment_type = p_type  and segment_name = p_segname  and SEGMENT_SPACE_MANAGEMENT <> 'AUTO' )  )  loop  dbms_space.free_blocks  ( segment_owner => p_owner,  segment_name => p_segname,  segment_type => p_type,  partition_name => p_partition,  freelist_group_id => 0,  free_blks => l_free_blks );  end loop;  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( 'Free Blocks', l_free_blks );  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;  /

从原版来看，根据dba_tablespaces、dba_segments检索出表空间的名称，使用dbms_space包的free_blocks和unused_space计算相应空间，格式化输出，其中有一点需要注意，就是只会统计SEGMENT_SPACE_MANAGEMENT <> 'AUTO'的表空间，即MANUAL手工管理的表空间。

这个脚本最开始是2002年针对9i版本发布的帖子，

直到2014年，还有人跟帖，足以见其影响力，

我们用实验来体会一下，创建测试表，

执行存储过程，

删除数据，

空间不会释放，

truncate数据，

此时表空间则被初始化，

我们看几个改良的版本，

(1) 惜分飞版本，

http://www.xifenfei.com/2011/09/tom%E7%9A%84show_space%E8%BF%87%E7%A8%8B%E4%BD%BF%E7%94%A8.html

create or replace procedure show_space ( p_segname_1 in varchar2, p_owner_1 in varchar2 default user, p_type_1 in varchar2 default 'TABLE', p_space in varchar2 default 'AUTO', p_analyzed in varchar2 default 'Y' ) 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; /

其特点就是，可以接受AUTO类型管理的表空间，可以接受I、T、C作为索引、堆表和聚簇表的简写，如果段已被分析，则回显中会包含空闲空间块百分比，更直观展示表的使用情况，

(2) Dave版本

http://blog.csdn.net/tianlesoftware/article/details/8151129

CREATE OR REPLACE PROCEDURE show_space (    p_segname_1     IN VARCHAR2,    p_type_1        IN VARCHAR2 DEFAULT 'TABLE', p_space         IN VARCHAR2 DEFAULT'MANUAL',    p_analyzed      IN VARCHAR2 DEFAULT 'N', p_partition_1   IN VARCHAR2 DEFAULTNULL,    p_owner_1       IN VARCHAR2 DEFAULT USER)    AUTHID CURRENT_USER AS    p_segname              VARCHAR2 (100);    p_type                 VARCHAR2 (30);    p_owner                VARCHAR2 (30);    p_partition            VARCHAR2 (50);    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);    p_owner := UPPER (p_owner_1);    p_type := p_type_1;    p_partition := UPPER(p_partition_1);    IF (p_type_1 = 'i' OR p_type_1 ='I')    THEN       p_type := 'INDEX';    END IF;    IF (p_type_1 = 't' OR p_type_1 ='T')    THEN       p_type := 'TABLE';    END IF;    IF (p_type_1 = 'tp' OR p_type_1 ='TP')    THEN       p_type := 'TABLE PARTITION';    END IF;    IF (p_type_1 = 'ip' OR p_type_1 = 'IP')    THEN       p_type := 'INDEX PARTITION';    END IF;    IF (p_type_1 = 'c' OR p_type_1 ='C')    THEN       p_type := 'CLUSTER';    END IF;    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);    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,                              partition_name      =>p_partition,                              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,                              partition_name       =>p_partition,                               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 ('Thesegment is analyzed');       p ('0% -- 25% free spaceblocks', l_fs1_blocks);       p ('0% -- 25% free spacebytes', l_fs1_bytes);       p ('25% -- 50% free spaceblocks', l_fs2_blocks);       p ('25% -- 50% free spacebytes', l_fs2_bytes);       p ('50% -- 75% free spaceblocks', l_fs3_blocks);       p ('50% -- 75% free spacebytes', l_fs3_bytes);       p ('75% -- 100% free spaceblocks', l_fs4_blocks);       p ('75% -- 100% free spacebytes', 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; /

这个版本是(1)的基础上支持了分区，以及接受IP和TP作为索引分区和表分区的简写。

另外，以下文章中有类似show_space的改良版，但逻辑原理基本一致，可以根据自己的需求，选择适合自己的一个版本，

http://blog.csdn.net/indexman/article/details/47207987

http://blog.csdn.net/huang_xw/article/details/7015349

总结：

1. show_space这个存储过程可以方便我们统计表/索引/聚簇表等段的使用情况，不用写一些SQL来实现此目标。

2. show_space有不同版本，有的支持分区，有的支持各种不同段的简写，有的支持细粒度的统计，根据自己的需求，选择一款适合自己的版本，了解其中的实现原理，将工具的设计思想，据为己用，触类旁通，甚至可以进行一些改造。