Undo Segments In Undo Table Space
Nov 29, 2012Can we find out no of undo segments in undo Table space ? If so , how to find? what's their max limit ?
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Alter Table Fails - Ran Out Of Undo Space?
Jun 11, 2009I want to alter a very large table.
ALTER TABLE MYTABLE ADD
(
ENTRY_TSTMP DATE DEFAULT SYSDATE NOT NULL
)
My table is very large and I am getting an error saying I am out of undo space.
The dba says the undo space is as big as the table.
Undo Table Space Not Working - REDO Being Generated?
Feb 14, 2013I am using Oracle 10.2.0.3. Since yesterday i am seeing a session with sid 1160 using undo tablespace but not able to find how much it is using .I need to know which session and from which module and how much is the Undo being used by those sessions. I have tried searching but all the queries provide me with some different results each time.
Also i need the same information for REDO being generated .
Server Administration :: Sizing Undo Tablespace And Setting Undo-retention?
Jan 30, 2004regarding sizing undo tablespace and undo_retention parameter.we have to implement the database in production system with 40 users but how much space should be allocated to undo tablespace is there any propotions related to virtual memory and the
parameter.i have gone thru oracle doc's and some related sites.its an ERP aplications that contains 20 modules .I am an new one to this dba level
Performance Tuning :: Undo Space?
Jan 15, 2012Query to find out who is eating up most of the undo space and what query he is running..
View 3 Replies View RelatedWhat Happens When UNDO Space Is Full / Transaction Takes More Time To ERROR
Jan 26, 2011I have a long running transaction (more than 3 hours), and at the same time other operations are occurring on different tables, using the same UNDO space.
Sometimes we see ORA-30036, but this error occurs very late in the process. The transaction normally takes 3 hours, but when UNDO space is full, we do not get ORA-30036 upto 8 hours or 9 hours of process.
I am wondering what could be happening in the background, when UNDO space is full, which makes the transaction to extend upto 8 hours or 9 hours (pl. note, this transaction gets completed within 3 hours normally). This is in 11g, UNDO space is managed manually.
SQL & PL/SQL :: Undo Dropped Column From Table
Jul 13, 2013Flashback query is working fine for dropped table,but throwing error when trying to get back the previous date by dropping a column from a table.
FLASHBACK TABLE emp TO TIMESTAMP TO_TIMESTAMP('2013-07-13 05:00:00', 'YYYY-MM-DD HH24:MI:SS')
SQL Error: ORA-01466: unable to read data - table definition has changed
Is that a limitation of Oracle by not having query to flashback a column but a table.
SQL & PL/SQL :: How To Undo A Drop Table Operation
Feb 24, 2013How do I perform Undo a drop table operation?
View 12 Replies View RelatedSQL & PL/SQL :: Find Out How Much Undo Will Be Generated By DML / DDL
Mar 29, 2010How to find out how much undo will be generated by a dml / ddl statement in Oracle 9i? With Oracle 10g we can use the famous mystat.sql and mystat2.sql with argument as 'undo change vector size'.
However with Oracle 9i there is no statname as 'undo change vector size'
Undo Tablespace Size
Jun 6, 2012At a time my 20 GB undo tablespace was full. So i increased the tablespace size upto 48 GB. Then i saw 45 GB was used. Then i changed undo_retention=60. After that am seeing that 48 GB is full.
1) why it's happened?
2) Here what is the effect of undo_retention=60
3) How to resolve?.
Can Undo Tablespace Be Too Large
Apr 26, 2013Can an undo tablespace be too large and actually hurt performance? I have seen a system with a dedicated 1 TB drive for undo tablespace (no guarantee) with an undo_retention of 7 days. Would this hurt performance? What about setting an undo_retention of 24 hours with no guarantee? The only mention I could find online said that it would not hurt performance but I wanted to double check. You would think that Oracle does not care if it deletes the undo at 15 minutes or if it deletes the undo at a later date such as 7 days later and the performance should stay the same.
View 3 Replies View RelatedUndo Tablespace Management
Apr 23, 2013I am trying to drop 90 columns from a big partitioned table. I was trying a physical drop first and since it is taking longer time I decided make the columns unused state and drop them. However I was able to set them to unused state.
Now I am trying to drop those unused columns from the table, it is running since 22hours Apporox. I am keep increasing the undo tablespace to retain the undo data.
I also have decreased the undo_retention to 300 from 900.
My question is there any better way to drop these columns. And is there any way to flush out the data from undo.
Recovery Of Undo Tablespace?
Apr 2, 2013S:Solaris
DB:10g
I am simulating a recovery of drop undo tablespace. for the same I have done the following things:
1. Dropped the only undo datafile from the os level while the database was open.
2. Then I created a table and inserted and updated some values in it and I was also allowed to commit.
When I am updating the rows of the table,the before images must have been written to UNDO but in my case there is no UNDO datafile.
Undo Application During Instance Recovery?
Apr 10, 2013During rollback phase of instance recovery, where is the undo applied from:
- redo logs
or
- undo generated during redo application in roll forward phase?
While Dropping Old Undo Tablespace / Getting Error
Dec 23, 2012i Cannot drop old undo tablespace. While dropping the old undo tablespace we get an error
ERROR at line 1: ORA-01548: active rollback segment '_SYSSMU77$' found, terminate dropping tablespace
SQL> select tablespace_name, status, segment_name from dba_rollback_segs where status != 'OFFLINE';
TABLESPACE_NAME STATUS SEGMENT_NAME
------------------------------ ---------------- ------------------------------
SYSTEM ONLINE SYSTEM
APPS_UNDO NEEDS RECOVERY _SYSSMU77$
Increase Undo_retention Value Or Undo Tablespace Size?
Aug 18, 2010When i takeind export i got error like this..
ORA-39125: Worker unexpected fatal error in KUPW$WORKER.GET_TABLE_DATA_OBJECTS while calling DBMS_METADATA.FETCH_XML_CLOB [TABLE_DATA:"POS"."TBK_POS_FACT":"KROATL200404"]
ORA-01555: snapshot too old: rollback segment number 1 with name "_SYSSMU1$" too small"
from this can we increase the undo_retention value or undo tablespace size?
Difference Between Redo Logs And Undo Tablespace
Jan 17, 2007I'm an Oracle novice and from what I've read so far, it seems that you should be able to do rollbacks and data recovery using the redo logs. I'm having a difficulty understanding the need for the undo tablespace.
View 2 Replies View RelatedDifference Between Redo Logs And Undo Tablespace?
Apr 25, 2013it seems that you should be able to do rollbacks and data recovery using the redo logs. I'm having a difficulty understanding the need for the undo tablespace.
View 3 Replies View RelatedServer Administration :: Roll Of Undo In Recovery?
Aug 4, 2011what is the role of undo cache or undo tablespace in recovery?
View 3 Replies View RelatedServer Administration :: How To Undo Tablespace Size
Feb 7, 2011As the undo segments are used in round robin fashion, Is it possible that with varying load (concurrent users, size and number of transactions), the size of Undo tablespace on a particular day is less than the Undo tablespace size few days back, by any chance?
As a basic understanding I know that Undo is preserved for read consistency and transaction, instance recovery So if there are lot of transaction on a database on 05 Feb and before that, but there aren't any transactions on 6,7,8,9, then on 10th Feb can we see the Undo tablespace size is less than that of 05 Feb?
In the following case when data belonging to table is not required for any queries, transactions, even then the undo size is not restored upon dropping the table.
As such for large operations and batch processes shall we keep undo tablespace with files as 'Autoextend' with 'Maxsize' as 'Unlimited'?
SQL> select b.tablespace_name, Total_Kbytes_Available/1024 Tot_Mbytes_Available,
Kbytes_alloc/1024 Mbytes_allocated, kbytes_free/1024 Mbytes_Free_from_allocated,
((Kbytes_alloc - kbytes_free)*100/ Total_Kbytes_Available) Pctused
2 from ( select sum(bytes)/1024 Kbytes_free,
3 tablespace_name
4 from sys.dba_free_space
[code]....
Server Administration :: UNDO In Parameter File?
Dec 9, 2011I have a question ragarding undo tablespace. I want to ask that why only undo tablespace information we need to specify in parameter file. We do not specify any other tablespace information. Not even for temporary tablespace. Then why we need to give undo tablespace name while instance is creating.
View 5 Replies View RelatedSize Of Undo Tablespace Datafile Different From Same Files In OS
Jan 22, 2013why total size for undotbs1 is different from the acutal data file size in Operating system.
select tablespace_name, sum(bytes/1024/1024) from dba_data_files
where tablespace_name like 'UNDO%'
group by tablespace_name;
tablespacename total size
UNDOTBS1 2000
UNDOTBS2 7284
[code]....
TUNED_UNDORETENTION Undo Tablespace Is Not Fixed Size
Apr 14, 2013rdbms 11gr2 undo tablespace is not fixed size. and the undo guarantee is not set.should we set undo_retention to
select max(tuned_undoretention) from v$undostat ; to avoid 1555 error?
Server Administration :: Undo Info Of Insert Statement
Jun 24, 2012If we insert a row in a database table then the new row stays at database buffer cache in SGA (until commit), right?. The target table is not affected (before commit). The new row is saved after commit.
I saw a concepts at Sybex oracle 10g oca book (Page 406) as follows:
" INSERT statements use little space in an undo segment; only the pointer to the new row is stored in the undo tablespace. To undo an INSERT statement, the pointer locates the new row and deletes it from the table if the transaction is rolled back. "
My question is If the row is not saved at table before commit, if we issue rollback then how oracle delete from table? I think the new row is deleted from database buffer cache in SGA.
Server Administration :: Undo Tablespace Which Has Autoextend On Feature
May 18, 2011you have an undo tablespace which has autoextend on feature.after a timegap your undo tablespace presently is 100GB
here as a DBA what you will do?
Server Utilities :: Added A Datafile In Undo Tablespace
Apr 28, 2011When I am importing, I get these errors
IMP-00019: row rejected due to ORACLE error 1
IMP-00003: ORACLE error 1 encountered
ORA-00001: unique constraint (XXXXXXXXXXXXXXXX) violated
Column 1 2
Column 2 OFFLINE
[code]....
I added a datafile in undo tablespace (its an ASM database). I doubt that since I added the datafile to undo tablespace, I am getting this error.
Performance Tuning :: ORA-01555 Required Old Image Is Not In Undo
Sep 22, 2011I am getting the below error in alert log file,when my application calling a procedure.
ORA-01555 caused by SQL statement below (Query Duration=1576 sec, SCN: 0x09a2.5dda3165):
Fri Sep 16 16:33:40 2011
UPDATE SSPT_NETWORK_DETAILS SET INCLUDE_OFFERS = 'Yes' WHERE SESS_ID = SESS_ID
There is no ROLLBACK statement in my procedure. As per my understanding, the ORA-1555 error will occur,
1. The required old image is not in the undo,when we rollback the trasaction.
2. the select query may face this error because of delayed block cleanout concept.
But I don't know why this update statement causing this 1555 error?
Backup & Recovery :: UNDO Tablespace Deleted From OS Level?
Mar 24, 2013Operating System - WindowXP
oracle version 10.2.0.1
I was learning some recovery part in my home laptop. Database is in Archivelog, flashback mode. All of sudden, i deleted it from OS level with out taking backup of it.
When i tried to open database, it failed to start. Database is in mount mode.while trying to open, it gives message -
ORA-01157: cannot identify/lock data file 1 - see DBWR trace file
ORA-01110: data file 1: 'F:ORACLEPRODUCT10.2.0ORADATADBSYSTEM01.DBF'
I tried to create on file named "UNDOTBS01.DBF" but oracle is not recognizing it.
Real Application Clusters :: Possible To Have Three Undo Tablespaces For 2 Node
Oct 12, 2012Version: 11.2.0.2/RHEL 5.4
I was under the impression that you need only one UNDO Tablespace for each instance. But , for our 2-node RAC, I can see three Undo tablespaces.
SQL> select tablespace_name,status from dba_tablespaces where CONTENTS = 'UNDO';
TABLESPACE_NAME STATUS
------------------------------ ---------
UNDOTBS1 ONLINE
UNDOTBS2 ONLINE
UNDOTBS3 ONLINE
SQL> select distinct inst_id from gv$session;
INST_ID
----------
1
2
$ olsnodes -n
thclst214 1
thclst215 2
Server Administration :: How Oracle Implements Undo Management
Jul 31, 2010I have been reading various articles about the undo management. This basic concept of undo management is simple but how oracle implements it is bit harder for me to grasp.
What i have read and understood is that whenever a DML(Update, Delete, Insert) statement is issued by a user, the data is fetched from datafile to database buffer cache and at the same time a copy of the original data is saved in undo segment. Now if other users requests the same data, they are presented with the unchanged copy in the undo segment.
Now I have the following questions:
1) In case of Insert statement, what data is saved in undo segment. Is it the complete data in the table to which we want to insert the new row?
2)When the user issues DML statement, there are three copies of the same data, one in Memory (which is changed and not the same as original data), second in Undo segment (Which is unchanged copy of original data) and third in datafile file ( which is original data). What is the difference in the data in undo segment and data in datafile at this stage. Why are the other users presented with the data from undo segment rather than original data from the datafile to maintain read consistency.
3)When the user issues rollback, the changes made to the copy of data in memory are undone.The copies of data in memory and undo segment are now same?. What happens to the before change copy in undo segment. Is it still there or deleted.