Block in the Undo tablespace corruption

Similar Questions

• Changing data in the undo tablespace or db Oracle buffer cache

  Hello
  
  I have serious doubt in the feature of oracle architecture, when a user issues an update statement, the data blocks are transported to the db buffer cache and where the data changes are made? Made a copy data block is stored in the cache db pads and the changes are made to the block in the buffer cache? or the copy of the data block is stored in the undo tablespace and changes are made to the blocks in the undo tablespace?
  
  In singles, the changes to the data blocks are make to the db or undo tablespace buffer cache?
  
  
  Thanks in advance
  
  Kind regards
  007

  Did you have a look to the Internet for the answer?

  In short, if a trial Oracle wants to update a record in the table, it does:

  -Read the record to be changed in the buffercache
  -Audits (the record already locked, is the update allowed)
  -Put the folder (called image before) in a rollback in the UNDO tablespace segment
  -Writing redo information about this change in the UNDO tablespace
  -Lock the record
  -Write the change in registration in the buffer cache
  -Put the change also in the redo buffer
  S ' sit and wait... (for a commit or a rollback)

  When are committed:
  -Release the lock
  -Empty folder of restoration since the UNDO tablespace
  -Write a record of this change forward in the UNDO tablespace

  When rollback:
  -Release the lock
  -Rinse the record changed the buffercache
  -Read the original value
  -Empty folder of restoration since the UNDO tablespace
  -Write a record of this change forward in the UNDO tablespace

  It of here, some more specific complexity when a checkpoint occurs between the change and the commit / rollback or redo buffer has been emptied for redo files

  Please any other s/n, correct me if I'm wrong...

  See you soon
  FJFranken

• undo_segments in the undo tablespace

  (1) at least how undo_segments in undo tablespace?

  Is optimal?
  If I increase the size of the undo tablespace, undo_segments counts also have increased!

  Version of DB is 10g

  Hello

   

  The two time oracle maintains exactly 10 segments. (you can see nom_segment begins by _SYSSMU11)

  I'm not clear on what exactly 10 segments. I have undo tablespace of ~ 250 GB with 6676 stored in dba_rollback_segs.

  3) why undo tablespace with the only spaceMo 46,8125 '?

  
  

  (4) I mean why he is stiil 450Mo undo_retention even through time or same validation has occurred?

  Just Oracle - Doc

  Once a transaction is committed, the undo data are more necessary for purposes of recovery rollback or transaction. However, for consistent read purposes, long-running queries may require old undo information to produce older images of data blocks. In addition, the success of several Oracle Flashback features can also depend on the availability of the old cancellation information. For these reasons, it is desirable to keep the old information of cancellation for as long as possible.

  Introduction to the management of the automatic cancellation

  With undo tablespace, you would see extended with the status ACTIVE, EXPIRED, extents still to RUN.

  Active cancellation extended are used by transactions and will be always active, because they are needed for the restoration.

  Extensions has expired are not used by transactions, the data contained in these extended is committed and the time UNDO_RETENTION is passed, so it is not necessary for the coherence of reading and can be reused.

  Not expired extensions are extended no assets but honor UNDO_RETENTION. Transactions belonging to these bodies of cancellation are determined, but the retention time has failed, and it may be necessary for the coherence of reading!

  Paste the query result - below

  ! undo_extent_stat.SQL more

  status of collar for a30

  Select the State,

  round (sum_bytes / (1024 * 1024), 0) like MB,.

  Tour ((sum_bytes / undo_size) * 100, 0) as PERC

  Of

  (

  Select the State, sum (bytes) sum_bytes

  of dba_undo_extents

  Status group

  ),

  (

  Select sum (a.bytes) undo_size

  from dba_tablespaces c

  Join v$ tablespace b on b.name = c.tablespace_name

  Join v$ datafile on a.ts # b.ts = #.

  where c.contents = 'UNDO '.

  and c.status = 'ONLINE '.

  );

  Anand

• How to reduce the UNDO Tablespace

  Hello
  We had an UNDO Tablespace to 22 GB but it's using just 2GB. How to shrink the undo tablespace. We use the database in production cluster 3 node 10.2.0.4
  Is there is way we can worry about UNDO Tablespace or should I create an UNDO tablespace and assign the undo tablespace to DB and let fall the old CANCEL?
  How to ensure that the transactions are done and free to abandon the old CANCEL?
  That's what we must restart all three nodes each node has its own UNDO Tablespace.
  
  Need help on this issue.
  
  would appreciate your quick response.
  
  
  Thank you

  No you have not.

  concerning
  Mohamed

• The UNDO tablespace and its data file cannot be removed

  I would like to delete an UNDO tablespace after you have created a new, but can't. I could follow a large number of instructions TOM and others, but tablepspace is still listed in the State to RECOVER. Please see what I've done below. Your help will be appreciated.
  

  SQL > drop tablespace UNDOTBS2;
  Drop tablespace UNDOTBS2
  *
  ERROR on line 1:
  ORA-01548: active rollback segment "_SYSSMU29_1272378969$" found, terminate
  drop the tablespace

  SQL > drop rollback segment "_SYSSMU29_1272378969$";
  Drop rollback segment "_SYSSMU29_1272378969$".
  *
  ERROR on line 1:
  ORA-30025: DROP segment ' _SYSSMU29_1272378969$ ' (in the undo tablespace) not
  permit

  Have you tried that
  http://arjudba.blogspot.com/2008/08/ora-01548-active-rollback-segment.html

• Impossible to drop the undo tablespace

  Hello
  
  ORACLE VERSION: 11.1.0
  OPERATING SYSTEM: WINDOWS XP
  
  I have been uable to drop the undo tablespace. Here I create a new undo tablespace and trying to drop the old undo tablespace.
  
  I had given alter system set UNDO_TABLESPACE = newundo tablespace.
  
  And try to drop the old one and get the error like this
  

  SQL> create undo tablespace undotbs02 datafile 'F:\APP\POORNAPRASADS\ORADATA\ORCL\UNDOTBS02.dbf' size 200m;
  
  Tablespace created.
  
  SQL> sho parameter undo
  
  NAME                                 TYPE        VALUE
  ------------------------------------ ----------- ------------------------------
  undo_management                      string      AUTO
  undo_retention                       integer     900
  undo_tablespace                      string      UNDOTBS1
  SQL> alter system set undo_tablespace=undotbs02;
  
  System altered.
  
  SQL> sho parameter undo
  
  NAME                                 TYPE        VALUE
  ------------------------------------ ----------- ------------------------------
  undo_management                      string      AUTO
  undo_retention                       integer     900
  undo_tablespace                      string      UNDOTBS02
  SQL> drop tablespace undotbs1 including contents and datafiles;
  drop tablespace undotbs1 including contents and datafiles
  *
  ERROR at line 1:
  ORA-30013: undo tablespace 'UNDOTBS1' is currently in use
  
  
  SQL> drop tablespace undotbs1 including contents and datafiles;
  drop tablespace undotbs1 including contents and datafiles
  *
  ERROR at line 1:
  ORA-30013: undo tablespace 'UNDOTBS1' is currently in use

  There are active sessions that use of old undo segments. I think you should kill these sessions in order to relase these segments

  - - - - - - - - - - - - - - - - - - - - -
  Kamran Agayev a. (10g OCP)
  http://kamranagayev.WordPress.com
  [Step by step installation Oracle Linux and automate the installation by using Shell Script | http://kamranagayev.wordpress.com/2009/05/01/step-by-step-installing-oracle-database-10g-release-2-on-linux-centos-and-automate-the-installation-using-linux-shell-script/]

• It will frequently commit resolve ora-30036 (cannot extend the undo tablespace)

  I use 11.2.0.3 database. I confused on the use of validation to resolve ora-30036.

  I have the script in migration once that has many updates and I'm getting ORA-30036 (unable to extend segment by 4 in the "UNDOTBS" undo tablespace) .

  Our undo tablespace in NO mode autoextend and like this is just a one time event, we will not increase it.   He is currently 6 GB.

  We would commit determination ORA-30036 in my case? If not why? Is there a better solution to solve it.

  
  

  When I say commit frequent, I won't commit after each line, I just want to commit after may be million lines, so that my active cancellation extend turn into cancellation remaining will extend and Oracle will be able to use it in case of pressure of space.

  
  

  Note:

  UNDO_MANAGEMENT: AUTO

  UNDO_RETENTION: 2700

  Undo tablespace retention is NOGAURANTEE.

  I have the script in migration once that has many updates and I'm getting ORA-30036 (unable to extend segment by 4 in the "UNDOTBS" undo tablespace).

  Our undo tablespace in NO mode autoextend and like this is just a one time event, we will not increase it.   He is currently 6 GB.

  Why don't you increase it?

  You must use the correct size of UNDO necessary for the work that will be done.

  A lot of shops to create a for big lots new UNDO tablespace and then switch to it for batch processing. Once the task is completed, they switch back to the normal UNDO. That prevents the normal RETURN of autoextending far where it is normally necessary:

  ALTER SYSTEM SET UNDO_TABLESPACE

• ORA-01555 - Tuning for the UNDO tablespace.

  Dear DBA Kings/Queens,
  
  I often "ORA-01555 snapshot too old error" due to the special delete statement. Which removes the lines about 50 000 all day as a batch. Eventhough, I reduced to 50 000 to 10 000 and 1000. No luck.
  Can someone tell me how to set UNDO tablespace.
  -----------------------------------------------------------------------------
  Oracle9i Enterprise Edition Release 9.2.0.7.0 - 64 bit Production
  PL/SQL Release 9.2.0.7.0 - Production
  CORE 9.2.0.7.0; Production
  AMT for Solaris: release 9.2.0.7.0 - Production
  NLSRTL Version 9.2.0.7.0 - Production
  -----------------------------------------------------------------------------
  SQL > show Cancel parameter
  
  VALUE OF TYPE NAME
  ------------------------------------ ----------- ------------------------------
  UNDO_MANAGEMENT string AUTO
  UNDO_RETENTION integer 10800
  undo_suppress_errors Boolean TRUE
  undo_tablespace string UNDOTBS1
  -----------------------------------------------------------------------------
  
  Size in GB:
  
  TOTAL USED FREE USED_PCNT NOM_TABLESPACE
  ------------------------------ ---------- ---------- ---------- ----------
  UNDOTBS1 13.5; 1.34; 12.17; 9.89

  Which removes the lines about 50 000 all day as a batch

  Has often committed?
  -do not commit frequently.

  -Increase the setting "undo_retention.

  -reduce the duration of operation (plan use of execution to check your query)... perhaps may create index. Or to commit all the 5000 rows

  -For collecting statistics on the table

  Edited by: Surachart Opun (HunterX) July 23, 2009 12:04 AM

• FLASH BACK TO THE WIDE FOR UNDO TABLESPACE?

  Hi all
  As my evryday increasingly, Undo tablespace 2 GB and NOW he reached 19.
  The database size is 6 GB
  
  using the Oracle 10 g Release 2 without patch Set (version 1002000100) on Hp-Unix OS
  
  Can I use the Undo tablespace with FLASHBACK OFF option?
  
  What are the consequences to extinguish the FLAME,
  
  Can we use this type of tablespace Undo with Flashback OFF?
  
  
  CREATE THE UNDO TABLESPACE UNDOTBS03 DATAFILE
  ' / app/oracle/product/oradata/prod/undotbs03.dbf' SIZE 1000 M AUTOEXTEND OFF
  ONLINE
  RETENTION NOGUARANTEE
  8K BLOCKSIZE
  FLASHBACK
  
  
  Thank you very much

  The (increasing) size of the Undo Tablespace has no impact on performance.

  One of the possibilities:
  He'll do backups take longer... so if you perform backups online, then the lengthy backup may be creeping in the moment of the request of the user.

• Undo Tablespace queries

  Hi all
  
  I am little confused with reading on the undo tablespace. So I need some clarification
  
  1. There are 2 undo tablespace in our application. Could someone explain to me how the 2 undo tablespace? I've not found details about it.
  2. both the undo tablespace is used at 100%. Where the the new transaction will go? New operation will force the blocks used to be exceeded if necessary?
  3. what should be the ideal size of the tablespace undo compared to the total storage size?
  4. is the log archive associated with space undotable? If Yes, then when archiving logs getting generated?
  
  Thank you

  1. in a database of CARS, each Instance must have it's own Undo Tablespace.
  In a database not RAC (single instance), only one Undo Tablespace can be active at any time. The Undo Tablespace would be idle but can be switched by an ALTER SYSTEM SET UNDO_TABLESPACE command.

  2. even if an Undo Tablespace is 'used 100% ' Oracle can expire (and even drop) on old extents and segments that are no longer needed by the value of Undo_Retention. Thus, data undo for older transactions that are committed (more than Undo_Retention period has elapsed since the validation) will be overwritten.

  3. There is no "ideal size. Undo sizing is based on transaction volumes, fluctuations in the volume of transactions, query patterns etc.

  4. No, there is no direct relationship between the two. However, any cancellation that is generated is also written again - that is to say redo Undo catches as it captures changes made to Tables, indexes etc..

  I suggest you read the Oracle documentation concepts to
  http://download.Oracle.com/docs/CD/E11882_01/server.112/e16508/TOC.htm

  Hemant K Collette
  http://hemantoracledba.blogspot.com

• Problems with UNDO tablespace

  Hello
  
  DB_VERSION: 10.2.0.4
  OS_VERSION: Windows 2003 server
  
  SQL > show Cancel parameter
  
  VALUE OF TYPE NAME
  ------------------------------------ ----------- ----------------
  UNDO_MANAGEMENT string AUTO
  UNDO_RETENTION integer 900
  undo_tablespace string UNDOTBS1
  
  I know that UNDO tablespace stores the old image of o / old value when the cancellation of the user, the old value is returned to the user throgh UNDO.
  
  
  My UNDO tablespace grows up to 24GO as a developer frequently updates the database in the morning and in the evening.
  
  Basically, it runs a script to offset that includes the INSERT and UPDATE and it is important to extermely.
  
  Whenever the UNDO SCT is full, I create a new one with autoextend on, what happens if I do not autoextend?
  
  1. what would be the impact on queries, if I do like above I always created UNDO tablespace with autoextend 2Go on.
  
  2. What is the best time to drop the old UNDO tablespace?
  
  Thanks in advance.

  Dear user12000301,

  Firstly the undo tablespace is not just there to roll back the transaction. You can use the for recovery undo tablespace (roll back during the recovery of the instance), coherent reading and also for operations of blowback.

  If you have defined a tablespace undo with the goal of conservation of 15 minutes, but have fixed size then;

  http://download.Oracle.com/docs/CD/B19306_01/server.102/b14231/undo.htm

  +"+
  + The following points explain the exact impact of the undo retention UNDO_RETENTION parameter: +.

  + The UNDO_RETENTION parameter is ignored for a fixed size undo tablespace. The database can overwrite the information to cancel remaining when the tablespace space becomes low. +

  + For a tablespace undo with the option enabled AUTOEXTEND, the database tries to honor the minimum retention specified by UNDO_RETENTION period. When space is low, instead of crushing the cancellation information remaining, the self-aggrandizing tablespace' extends. If the MAXSIZE clause is specified for an auto-croissant undo tablespace when the maximum size is reached, the database can begin to replace the cancellation information remaining. +
  +"+

  Be careful with the settings to cancel it. The size, before you add the new data files in the tablespace, undo or autoextending for your pain, you must consider the DML that caused the growing undo tablespace. Necessaryly should generate redo or cancel? If so, know the total amount of undo blocks through the relevant DML.

  If you have created a with 2 GB undo tablespace and mark as CanGrow that the data file can be up to 32 GB. The DBCA you will create a petit_fichier undo tablespace but you can create another like bigfile and pretend the tablespace default undo for the operation.

  The best time to drop an undo tablespace is to wait at least undo_retention period of time has elapsed to make sure you don't need to have the copy of the coherent image transactions are committed. I think that the solution could be achieved as underlined Chinar but be careful on the active rollback segments in your database. You can also dynamically change the default undo tablespace anytime if the database uses the spfile.

  Hope that helps.

  Ogan

• recover missing (ORA-01092) UNDO tablespace

  I got ORA-01092 when starting the database
  
  SQL > startup
  ORACLE instance started.
  
  Total System Global Area 1367343104 bytes
  Bytes of size 1292468 fixed
  838862668 variable size bytes
  520093696 of database buffers bytes
  Redo buffers 7094272 bytes
  Mounted database.
  ORA-01092: ORACLE instance is complete. Disconnection forced
  
  I discovered that the UNDO tablespace is missing
  
  Alerts log shows this:
  
  My Oct 04 13:54:45 2010
  Setting the default value of the parameter parallel_max_servers
  160-135 because of the value of the process parameters (150)
  My Oct 04 13:54:45 2010
  Starting ORACLE instance (normal)
  LICENSE_MAX_SESSION = 0
  LICENSE_SESSIONS_WARNING = 0
  Diagram of SNA picked latch-free 2
  With the help of LOG_ARCHIVE_DEST_1 parameter value by default as D:\oracle\product\10.2.0\db_1\RDBMS
  Autotune undo retention is enabled.
  IMODE = BR
  ILAT = 18
  LICENSE_MAX_USERS = 0
  SYS audit is disabled
  ksdpec: called to the event 13740 before initialization of the event group
  Commissioning ORACLE RDBMS Version: 10.2.0.3.0.
  Parameters of the system with default values:
  process = 150
  __shared_pool_size = 813694976
  __large_pool_size = 8388608
  __java_pool_size = 8388608
  __streams_pool_size = 8388608
  SGA_TARGET = 1367343104
  control_files = D:\ORACLE\PRODUCT\10.2.0\ORADATA\AXPHQ01\CONTROL01. CTL, D:\ORACLE\PRODUCT\10.2.0\ORADATA\AXPHQ01\CONTROL02. CTL, D:\ORACLE\PRODUCT\10.2.0\ORADATA\AXPHQ01\CONTROL03. CTL
  DB_BLOCK_SIZE = 8192
  __db_cache_size = 520093696
  compatible = 10.2.0.3.0
  db_file_multiblock_read_count = 16
  UNDO_MANAGEMENT = AUTO
  undo_tablespace = UNDOTBS1
  Remote_login_passwordfile = EXCLUSIVE lock
  db_domain =
  dispatchers = (PROTOCOL = TCP) (SERVICE = AXPHQ01XDB)
  JOB_QUEUE_PROCESSES = 10
  audit_file_dest = D:\ORACLE\PRODUCT\10.2.0\ADMIN\AXPHQ01\ADUMP
  background_dump_dest = D:\ORACLE\PRODUCT\10.2.0\ADMIN\AXPHQ01\BDUMP
  user_dump_dest = D:\ORACLE\PRODUCT\10.2.0\ADMIN\AXPHQ01\UDUMP
  core_dump_dest = D:\ORACLE\PRODUCT\10.2.0\ADMIN\AXPHQ01\CDUMP
  db_name = AXPHQ01
  open_cursors = 300
  pga_aggregate_target = 419430400
  optimizerconnect_by_cost_based = FALSE
  allowlevel_without_connect_by = TRUE
  PMON started with pid = 2, OS id = 7988
  PSP0 started with pid = 3, OS id = 7964
  MA started with pid = 4, OS id = 6948
  DBW0 started with pid = 5, OS id = 7332
  LGWR started with pid = 6, OS id = 5128
  CKPT started with pid = 7, OS id = 7148
  SMON started with pid = 8, OS id = 5804
  RECCE has started with pid = 9, OS id = 3604
  CJQ0 started with pid = 10, OS id = 7084
  MMON started with pid = 11, OS id = 8448
  My Oct 04 13:54:46 2010
  commissioning 1 dispatcher (s) for '(ADDRESS =(PARTIAL=YES) (PROTOCOL = TCP))' network address...
  MMNL started with pid = 12, OS id = 4704
  My Oct 04 13:54:46 2010
  commissioning or shared server 1...
  My Oct 04 13:54:47 2010
  ALTER DATABASE MOUNT
  My Oct 04 13:54:51 2010
  Definition of embodiment of recovery target 2
  My Oct 04 13:54:51 2010
  Mount of redo thread 1, with mount id 4102419559
  My Oct 04 13:54:51 2010
  Database mounted in exclusive Mode
  Completed: ALTER DATABASE MOUNT
  My Oct 04 13:54:52 2010
  ALTER DATABASE OPEN
  My Oct 04 13:54:53 2010
  Beginning of thread 1 crash recovery
  parallel recovery started with 7 process
  My Oct 04 13:54:53 2010
  Scan again started
  My Oct 04 13:54:53 2010
  Complete scan again
  1 blocks again read, 0 data blocks need recovery
  My Oct 04 13:54:53 2010
  Request for reinstatement has started
  Thread 1: logseq 10520, block 2, CHN 8758774026015
  My Oct 04 13:54:53 2010
  Online Redo Log recovery: thread 1 mem Group 11 Seq 10520 reading 0
  Mem # 0: D:\ORACLE\PRODUCT\10.2.0\ORADATA\AXPHQ01\REDO11. JOURNAL
  My Oct 04 13:54:54 2010
  Completed request
  My Oct 04 13:54:55 2010
  Finished in crash recovery
  Thread 1: logseq 10520, block 3, RCS 8758774046017
  redo the 0 data blocks read, 1 0 written data blocks, blocks read
  My Oct 04 13:54:58 2010
  Thread 1 Advanced to record the sequence 10521
  Thread 1 is open to the sequence of journal 10521
  Currently journal # 12 seq # 10521 mem # 0: D:\ORACLE\PRODUCT\10.2.0\ORADATA\AXPHQ01\REDO12. JOURNAL
  Opening of redo thread 1
  My Oct 04 13:54:58 2010
  View MTTR is disabled, because FAST_START_MTTR_TARGET is not defined
  My Oct 04 13:54:58 2010
  SMON: enabling cache recovery
  My Oct 04 13:54:58 2010
  Errors in the d:\oracle\product\10.2.0\admin\axphq01\udump\axphq01_ora_1024.trc file:
  ORA-30012: undo tablespace "UNDOTBS1" there is not, or of the wrong type
  
  My Oct 04 13:54:58 2010
  Error 30012 happened during db open, close the database
  USER: termination litigation because of the error 30012
  My Oct 04 13:55 2010
  Errors in the d:\oracle\product\10.2.0\admin\axphq01\bdump\axphq01_pmon_7988.trc file:
  ORA-30012: undo tablespace "is not or of the wrong type
  
  My Oct 04 13:55 2010
  Errors in the d:\oracle\product\10.2.0\admin\axphq01\bdump\axphq01_reco_3604.trc file:
  ORA-30012: undo tablespace "is not or of the wrong type
  
  My Oct 04 13:55 2010
  Errors in the d:\oracle\product\10.2.0\admin\axphq01\bdump\axphq01_smon_5804.trc file:
  ORA-30012: undo tablespace "is not or of the wrong type
  
  My Oct 04 13:55 2010
  Errors in the d:\oracle\product\10.2.0\admin\axphq01\bdump\axphq01_ckpt_7148.trc file:
  ORA-30012: undo tablespace "is not or of the wrong type
  
  My Oct 04 13:55 2010
  Errors in the d:\oracle\product\10.2.0\admin\axphq01\bdump\axphq01_lgwr_5128.trc file:
  ORA-30012: undo tablespace "is not or of the wrong type
  
  My Oct 04 13:55:01 2010
  Errors in the d:\oracle\product\10.2.0\admin\axphq01\bdump\axphq01_mman_6948.trc file:
  ORA-30012: undo tablespace "is not or of the wrong type
  
  My Oct 04 13:55:01 2010
  Errors in the d:\oracle\product\10.2.0\admin\axphq01\bdump\axphq01_dbw0_7332.trc file:
  ORA-30012: undo tablespace "is not or of the wrong type
  
  My Oct 04 13:55:01 2010
  Errors in the d:\oracle\product\10.2.0\admin\axphq01\bdump\axphq01_psp0_7964.trc file:
  ORA-30012: undo tablespace "is not or of the wrong type
  
  Instance of stopped by USER, pid = 1024
  ORA-1092 marked during: ALTER DATABASE OPEN...

  Hello

  Do as suggested by Chinar or

  1. after installation of startup

  2. create spfile from pfile;

  3. immediate shu

  4. startup mount

  Then do all the steps as stated in my previous post.

  Anand

• Undo tablespace in oracle 10g

  Hi all;

  Hello!

  I'm confused about undo tablespace size.

  Under query showing my undo tablespace size is 120Mo.

  but DBA_TABLESPACE_USAGE_METRICS view showing the undo tablespace size is 4194302

  > > Check free space

  SQ > select t.tablespace, t.totalspace as ' TOTAL_SPACE (MB).

  round ((t.totalspace-fs.freespace), 2) as "USED_SPACE (MB)",
  FS. FreeSpace as "FREE_SPACE (MB).
  round (((t.totalspace-fs.freespace) /t.totalspace) * 100, 2) like "% used (s),"
  round ((fs.freespace/t.totalspace) * 100, 2) as "% free" of
  (select round (sum (d.bytes) /(1024 * 1024)) as totalspace,)
  tablespace dba_data_files d.tablespace_name d
  Group d.tablespace_name) t,.
  (select round (sum (f.bytes) /(1024 * 1024)) as freespace,)
  tablespace dba_free_space f.tablespace_name f
  Group of f.tablespace_name)
  FS where t.tablespace = fs.tablespace order of t.tablespace.

  
  

  TABLESPACE TOTAL_SPACE (MB) USED_SPACE (MB) FREE_SPACE (MB) % used free %

  ------------------------------ --------------- -------------- -------------- ---------- ----------

  EXAMPLE                                    100             68             32         68         32

  240 230 10 SYSAUX 95,83 4.17

  480 475 5 98.96 SYSTEM 1.04

  UNDOTBS1                                   120            120              0        100          0

  1005 75 930 USERS 7.46 92.54

  SQL > select * from dba_tablespace_usage_metrics, where nom_tablespace like '% UNDO;

  NOM_TABLESPACE USED_SPACE TABLESPACE_SIZE USED_PERCENT

  ----------------------------    ----------  ---------------  ------------

  UNDOTBS1                              440        4194302 .010490422

  This is because:

  Tablespace_size in DBA_TABLESPACE_USAGE_METRICS takes the maximum file size for CanGrow tablespace that matches maxblocks in dba_data_files.

  This is not the same value you can get from dba_data_files.

  DBA_TABLESPACE_USAGE_METRICS shows essentially the maximum size to which a data file can grow. And DBA_DATA_FILES (+ DBA_FREE_SPACE) the current size of the tablespace.

  Watch more document MOS (My Oracle Support):

  Difference in size of dba_data_files Tablespace and dba_tablespace_usage_metrics/V values $ Filespace_usage (Doc ID 455715.1)

• UNDO TABLESPACE MANAGEMENT

  Hello
  I'm trying to remove 90 columns of a partitioned table big. I was trying a physical decline first and since it takes more time, I decided take unused columns and drop them. However, I could put in unused condition.
  Now I'm trying to drop these unused columns in the table, it has run for 22hours approx. I'm keep increasing the undo tablespace to store the undo data.
  I have also diminished the undo_retention at 300 to 900.
  
  My question is there a better way to drop these columns. And is it possible to flush out the undo data.
  
  Your valuable response is greatly apprecaited.
  
  Thank you

  Hello

  Have you checked the link, can it help to use the checkpoint to the drop statement

  http://asktom.Oracle.com/pls/asktom/f?p=100:11:0:P11_QUESTION_ID:623063677753

• Question about Undo Tablespace?

  Hello;
  
  The necessary size of the undo tablespace is the number and size of the transactions that occur on the database. But I do not need to interview one of these transactions for a schema or table using flashback it is a way to disable transactions writing on a table or schema of undo tablespace?
  
  Published by: Ecimen on 04.Mar.2013 03:50
  
  Published by: Ecimen on 03:51 04.Mar.2013

  Ecimen wrote:

  Rob_J wrote:
  OK, it's fine, so what makes you say you build too UNDO? What is the problem you're trying to solve? Or you want to know if you could get back to CANCEL in writing?

  Our log tables generate too much to cancel because we need you connecting all these data (insert and update for the most part)... but we don't care about these log tables, we want to reduce the cancellation written for these tables logs so that we could use more flashback query timestamp older due to more space in the undo tablespace...

  I think I mentioned in my other two answers above that it is not possible to disable the generation of the cancellation, or at least I don't know that there is no way to do it! What you can do, if you are worried about the Undo tablespace grows, it is that make you a tablespace size Undo fixed by controlling the Undo data that are generated. You can use Cancel Advisor of the to do. With the Undo retention period of your proposed, she would like the size of the Undo tablespace tips and you can add about 20-30% extra size and you should be fine. But as I've already said too much, he has No way to stop generating cancellation.

  Aman...