oracle shrink file partition table,resize datafile

1、确保表所在表空间segment状态为自动：

   select tablespace_name,segment_space_management from dba_tablespaces;

    TABLESPACE_NAME                SEGMEN                                          
     ------------------------------ ------                                          
      SYSTEM                         MANUAL                                          
      UNDOTBS1                       MANUAL                                          
      SYSAUX                         AUTO                                            

2、确保表enable了row movement;

    select a.row_movement,a.* from all_tables a
         where  a.TABLE_NAME=tb_name '

 

   alter table tb_name enable row movement;

 

3、shrink table

  

Examples

Shrink a table and all of its dependent segments (including LOB segments):

ALTER TABLE employees SHRINK SPACE CASCADE;

Shrink a LOB segment only:

ALTER TABLE employees MODIFY LOB (perf_review) (SHRINK SPACE);

Shrink a single partition of a partitioned table:

ALTER TABLE customers MODIFY PARTITION cust_P1 SHRINK SPACE;

Shrink an IOT index segment and the overflow segment:

ALTER TABLE cities SHRINK SPACE CASCADE;

Shrink an IOT overflow segment only:

ALTER TABLE cities OVERFLOW SHRINK SPACE;

4、resize datafile

 

计算datafile可以resize收缩的空间.
col name for a40
col 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;' ResizeCMD
from v$datafile a,
     (select file_id,max(block_id+blocks-1) HWM
       from dba_extents
       group by file_id) b
where a.file# = b.file_id(+)
and (a.bytes - HWM *block_size)>0
order 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;' ResizeCMD
from 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) b
where a.file# = b.file_id(+)
and (a.bytes - HWM *block_size)>0
order 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$tempfile a,
     (select tmsize.maxblk*bk.value/1024/1024 siz from
         (select nvl(max(segblk#),128) maxblk  from v$sort_usage) tmsize,
         (select value From v$parameter where name = 'db_block_size') bk) b

  

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参考:

---MOVE LOGSEGMENT TO NEW TABLESPACE,根据实际检验LOBINDEX会随着相应的LOBSEGMENT自动移动
ALTER TABLE USERNAME.TABLE_NAME MOVE LOB(LOB_COLUMN) STORE AS (TABLESPACE NEW_TABLESPACE)