简述收缩表空间的办法

2012.10.17 来源: 互联网大字

我们来看一下如何收缩表空间，其实方法很简单。*先我们先计算datafile可以resize收缩的空间.col name for a40col resizecmd for a80

select a.file#,a.name,a.bytes/1024/1024 CurrentMB, ceil(HWM * a.block_size)/1024/1024 ResizeTo, (a.bytes - HWM * a.block_size)/1024/1024 ReleaseMB, 'alter database datafile '''||a.name||''' resize '|| ceil(HWM * a.block_size/1024/1024) || 'M;' ResizeCMDfrom v$datafile a, (select file_id,max(block_id+blocks-1) HWM from dba_extents group by file_id) bwhere a.file# = b.file_id(+)and (a.bytes - HWM *block_size)>0order by 5

如果只是想对某个表个间的datafile resize,可采用:select a.file#,a.name,a.bytes/1024/1024 CurrentMB, ceil(HWM * a.block_size)/1024/1024 ResizeTo, (a.bytes - HWM * a.block_size)/1024/1024 ReleaseMB, 'alter database datafile '''||a.name||''' resize '|| ceil(HWM * a.block_size/1024/1024) || 'M;' ResizeCMDfrom v$datafile a, (select file_id,max(block_id+blocks-1) HWM from dba_extents where file_id in (select b.file# From v$tablespace a ,v$datafile b where a.ts#=b.ts# and a.name='MP2000') group by file_id) bwhere a.file# = b.file_id(+)and (a.bytes - HWM *block_size)>0order by 5

计划tempfile可以resize的空间.on apply that have only one tempfile

select 'alter database tempfile '''||a.name ||''' reize '||b.siz||'M;' from v$tempfile a, (select tmsize.maxblk*bk.value/1024/1024 siz from (select nvl(max(segblk#),128) maxblk from v$***t_usage) tmsize, (select value From v$parameter where name = 'db_block_size') bk) b

投稿作者：孤芳不自赏46

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简述收缩表空间的办法

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