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的show_space过程使用.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。
