Complete solution instance of Oracle shrink table space

Catalog

remarks :

One . demand

Two . Solution

2.1 Clean up expired data

2.2 Shrink the table space

2.3 Clean up table fragments

2.4 Directly put the relevant table drop fall

2.5 Move other tables under this table space out of this table space

summary

remarks :

Oracle 11.2.0.4

One . demand

There is a log library recently , It takes up a lot of space , Need to clean up history , Then shrink the space .

As shown in the figure below ,4T We've almost run out of space .

Two . Solution

The first thought is to clean up the data for more than half a year , then resize Table space .

2.1 Clean up expired data

Because the table of business is tablename_yearmonth Format , for example log_202204, A watch every month , So go straight to truncate that will do .

Large table found :

select t.segment_name,t.BYTES/1024/1024/1024 GB,t.segment_typefrom user_segments twhere t.segment_type in ('TABLE','TABLE PARTITION')order by nvl(t.BYTES/1024/1024/1024,0) desc;

truncate The big table :

select 'truncate table '|| t.TABLE_NAME ||';' from user_tables t where t.TABLE_NAME like 'LOG%';2.2 Shrink the table space select a.tablespace_name,a.file_name,a.totalsize as totalsize_MB,b.freesize as freesize_MB,'ALTER DATABASE DATAFILE ''' || a.file_name || ''' RESIZE ' ||round((a.totalsize - b.freesize) + 200) || 'M;' as "alter datafile"from (select a.file_name,a.file_id,a.tablespace_name,a.bytes / 1024 / 1024 as totalsizefrom dba_data_files a) a,(select b.tablespace_name,b.file_id,sum(b.bytes / 1024 / 1024) as freesizefrom dba_free_space bgroup by b.tablespace_name, b.file_id) bwhere a.file_id = b.file_idand b.freesize > 100and a.tablespace_name in ('TBS_LOG_DATA')order by a.tablespace_name

Take the next step alter datafile Copy the statement and execute :

Some report errors :

ORA-03297: file contains used data beyond requested RESIZE value

2.3 Clean up table fragments

Because I use truncate, Theoretically, it will not be affected by high water level , I found several blogs on the Internet , It also means to lower the high water level of the meter , Clean up table fragments .

select 'alter table '||t.TABLE_NAME||' enable row movement;', 'alter table '||t.TABLE_NAME||' shrink space cascade;' from user_tables t where t.TABLE_NAME like 'LOG%';

After cleaning up the debris , Re execution , Is still an error .

2.4 Directly put the relevant table drop fall select 'drop table '|| t.TABLE_NAME ||'purge;' from user_tables t where t.TABLE_NAME like 'LOG%';

drop After dropping the meter , Re execution , Is still an error .

2.5 Move other tables under this table space out of this table space

Omnipotent itpub There is a blog on :

Truncate table perhaps drop table Shrink data files , I often meet ORA-03297: file contains used data beyond requested RESIZE value Inquire about dba_free_space There is also free space . After inquiry MOS(Doc ID 1029252.6) hear

If you have a large extent in the middle of a datafile, and some object taking up room at the end of the datafile, you can use the query FINDEXT.SQL below to find this object. If you export this object, then drop it, you should then free up contiguous space at the end of your datafile so you will be able to resize it smaller.

Make sure you leave enough room in the datafile for importing the object back into the tablespace.

It means if you are free extent If it's in the middle of the file , Cannot proceed at this time resize , The tail must be object drop Then rebuild Again resize datafile. The following is my test ;

 [[email protected] ~]$ sqlplus / as sysdbaSQL*Plus: Release 10.2.0.1.0 - Production on Wed Jul 31 11:10:41 2013Copyright (c) 1982, 2005, Oracle.  All rights reserved.Connected to:Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - 64bit ProductionWith the Partitioning, OLAP and Data Mining optionsSQL> create tablespace test2 datafile '/u01/app/oracle/oradata/orcl/test2.dbf' size 10M autoextend on next 1M;Tablespace created.SQL> create table tab1 tablespace test2 as select * from dba_objects;Table created.SQL> select file#,name,bytes/1024/1024 bytes from v$datafile where name like '%test2%';FILE# NAME                                                         BYTES----- ------------------------------------------------------------ -----   23 /u01/app/oracle/oradata/orcl/test2.dbf                          11SQL> create table tab2 tablespace test2 as select * from dba_objects;Table created.SQL> select file#,name,bytes/1024/1024 bytes from v$datafile where name like '%test2%';FILE# NAME                                                         BYTES----- ------------------------------------------------------------ -----   23 /u01/app/oracle/oradata/orcl/test2.dbf                          21SQL> select SEGMENT_NAME,FILE_ID,EXTENT_ID,BLOCK_ID,blocks from dba_extents where file_id=23 order by BLOCK_ID;SEGMENT_NA    FILE_ID  EXTENT_ID   BLOCK_ID     BLOCKS---------- ---------- ---------- ---------- ----------TAB1               23          0          9          8TAB1               23          1         17          8TAB1               23          2         25          8TAB1               23          3         33          8TAB1               23          4         41          8TAB1               23          5         49          8TAB1               23          6         57          8TAB1               23          7         65          8TAB1               23          8         73          8TAB1               23          9         81          8TAB1               23         10         89          8SEGMENT_NA    FILE_ID  EXTENT_ID   BLOCK_ID     BLOCKS---------- ---------- ---------- ---------- ----------TAB1               23         11         97          8TAB1               23         12        105          8TAB1               23         13        113          8TAB1               23         14        121          8TAB1               23         15        129          8TAB1               23         16        137        128TAB1               23         17        265        128TAB1               23         18        393        128TAB1               23         19        521        128TAB1               23         20        649        128TAB1               23         21        777        128SEGMENT_NA    FILE_ID  EXTENT_ID   BLOCK_ID     BLOCKS---------- ---------- ---------- ---------- ----------TAB1               23         22        905        128TAB1               23         23       1033        128TAB1               23         24       1161        128TAB2               23          0       1289          8TAB2               23          1       1297          8TAB2               23          2       1305          8TAB2               23          3       1313          8TAB2               23          4       1321          8TAB2               23          5       1329          8TAB2               23          6       1337          8TAB2               23          7       1345          8SEGMENT_NA    FILE_ID  EXTENT_ID   BLOCK_ID     BLOCKS---------- ---------- ---------- ---------- ----------TAB2               23          8       1353          8TAB2               23          9       1361          8TAB2               23         10       1369          8TAB2               23         11       1377          8TAB2               23         12       1385          8TAB2               23         13       1393          8TAB2               23         14       1401          8TAB2               23         15       1409          8TAB2               23         16       1417        128TAB2               23         17       1545        128TAB2               23         18       1673        128SEGMENT_NA    FILE_ID  EXTENT_ID   BLOCK_ID     BLOCKS---------- ---------- ---------- ---------- ----------TAB2               23         19       1801        128TAB2               23         20       1929        128TAB2               23         21       2057        128TAB2               23         22       2185        128TAB2               23         23       2313        128TAB2               23         24       2441        128

50 rows selected.

Block_id Is a continuous

SQL> truncate table tab1  2  ;Table truncated.SQL> select * from dba_free_space where file_id=23;TABLESPACE_NAME         FILE_ID   BLOCK_ID      BYTES     BLOCKS RELATIVE_FNO-------------------- ---------- ---------- ---------- ---------- ------------TEST2                        23         17 ##########       1272           23TEST2                        23       2569 ##########        120           23

Have original tab1 Of free blocks 1272

SQL> alter database datafile '/u01/app/oracle/oradata/orcl/test2.dbf' resize 12M;alter database datafile '/u01/app/oracle/oradata/orcl/test2.dbf' resize 12M*ERROR at line 1:ORA-03297: file contains used data beyond requested RESIZE value

Unable to proceed resize

The following tab1 drop Retest

SQL> drop table tab1 purge;Table dropped.SQL> alter database datafile '/u01/app/oracle/oradata/orcl/test2.dbf' resize 12M;alter database datafile '/u01/app/oracle/oradata/orcl/test2.dbf' resize 12M*ERROR at line 1:ORA-03297: file contains used data beyond requested RESIZE value

Still wrong

then truncate tab2 Retest

SQL> truncate table tab2;Table truncated.SQL> select * from dba_free_space where file_id=23;TABLESPACE_NAME         FILE_ID   BLOCK_ID      BYTES     BLOCKS RELATIVE_FNO-------------------- ---------- ---------- ---------- ---------- ------------TEST2                        23          9 ##########       1280           23TEST2                        23       1297 ##########       1392           23SQL> alter database datafile '/u01/app/oracle/oradata/orcl/test2.dbf' resize 12M;Database altered.SQL> alter database datafile '/u01/app/oracle/oradata/orcl/test2.dbf' resize 6M;alter database datafile '/u01/app/oracle/oradata/orcl/test2.dbf' resize 6M*ERROR at line 1:ORA-03297: file contains used data beyond requested RESIZE value

At this time, it can only shrink tab2 Space But not shrink tab1 Space

And then again drop tab2

SQL> drop table tab2 purge  2  ;Table dropped.SQL> alter database datafile '/u01/app/oracle/oradata/orcl/test2.dbf' resize 6M;Database altered.SQL> alter database datafile '/u01/app/oracle/oradata/orcl/test2.dbf' resize 1M;Database altered.

Can shrink tab1 Space

note:

Shrinking data files is related to two factors

1 Lower the high water level

2 free extent stay datafile Tail of

This article directly explains the second

If you are free extent If it's in the middle of the file , Cannot proceed at this time resize , The tail must be object drop Then rebuild Again resize datafile.

That is to say, the user writes other tables in the same period , Also under this data file , Then you can't resize.

Move other tables to users Table space :

select 'alter index '||index_NAME||' rebuild tablespace users;' from user_indexes where TABLE_NAME not like 'LOG_%';select 'alter table '||TABLE_NAME||' move tablespace users;' from user_tables where TABLE_NAME not like 'LOG_%';

Run compressed space again , success

2.6 View compressed space

You can see that there are more 2.1T Space

Shrinking space, running speed is good ,50 Multiple data files , Compress in a few minutes .

summary

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