NAME TYPE VALUE ------------------------------------ ----------- ------------------------------ undo_management string AUTO undo_retention integer 96000 undo_tablespace string undo
Following are the details in AWR report (00:00 til 01:00 of 21-Apr-2013) .... not thet the error was produced at 00:42
Undo Segment Summary DB/Inst: DBCPY/dbcpy01 Snaps: 18853-18854 -> Min/Max TR (mins) - Min and Max Tuned Retention (minutes) -> STO - Snapshot Too Old count, OOS - Out of Space count -> Undo segment block stats: -> uS - unexpired Stolen, your - unexpired Released, uU - unexpired reUsed
[code]....
Undo Advisor information taken 'now' is as following
SQL> select dbms_undo_adv.longest_query(sysdate-2,sysdate) from dual; DBMS_UNDO_ADV.LONGEST_QUERY(SYSDATE-2,SYSDATE) ---------------------------------------------- 379650 SQL> select dbms_undo_adv.required_retention from dual;
[code]....
In above situation what should be my first choice (assuming increasing space is not an issue) - increase undo tablespace or increase undo retention?
If latter is the choice then what should be the value? Because as I understand present 96000 value is taken as lower limit and because of auto tuning the actual value (TUNED_UNDORETENTION) being used was 345600 In that case shall I set it to something > max(maxquerylen) i.e 379,650 + X?Or I shall increase the undo tablespace size?
From Undo Advisor output it looks to me that even if I increase the undo retention to 379650 current undo size will be able to support it (may be at the expense of DMLs)Is that right?
At 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?.
As 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'?
regarding 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
I am trying to increase the size of sga or you can say that i want to make my sga in automatic memory management...Following is the steps i am trying
SQL> show parameter sga_max_size;
NAME TYPE VALUE ------------------------------------ ----------- ------------------------------ sga_max_size big integer 96M SQL>
after that i am trying to increase the size
SQL> alter system set sga_max_size = 200m; alter system set sga_max_size = 200m * ERROR at line 1: ORA-02095: specified initialization parameter cannot be modified
I have Oracle 11gR2 running on windows xp machine. Windows xp has total size of 150 GB and free space of 95 GB.
I checked the size of the database that I created. It showed the total size of the database as 2 GB and used space as 2 GB. If I want to increase the total size of the database to 50 GB, what should i do? Now which is the disk space size? Windows or Oracle?
I am executing a plsql procedure and trying to increase buffer size to display all characters, procedure is given below:
create or replace procedure prc_p(prm_t1 in VARCHAR2, prm_t2 in VARCHAR2, prm_tab in varchar2 ) AUTHID CURRENT_USER as str_sql VARCHAR2 (4000); [code]..........
We had a database (DB A)that is having version 9.2.0.6.0.This DB is having multiple tables and volume of 6 million in individual tables.Another database is also 9.2.0.6.0 (DB B), this DB has Mviews pointing to DB A. Mviews are refreshed in every 15 mins, with fast refresh option in 90% cases and remaining having complete refresh.
Last weekend we have migrated DB 2 to version 10.2.0.4.0 - 64bi and on another server.After version upgrade and DB migration complete refresh was done once for all mviews.
Now DB A is generating huge amount of archive log and also it's UNDO space is getting fully consumed causing performance issue and DB hang.what has gone wrong and what we can do to improve response of DB A and also to reduce size of Archive log ?
We have a table emp_details with 23772889 records. Our requirement is to increase few of the columns size in the table emp_details. We are following the below alter statement which is taking around 2 hours of time.
Can 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.
I 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.
I am using apex 4.1. I have this interactive report and i would like to make the text inside the report bigger and bolder. I have seen different examples of using css but none have worked for me. If you have any other way to do this or can give me a detailed way of using css!
i 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$' found, terminate dropping tablespace
SQL> select tablespace_name, status, segment_name from dba_rollback_segs where status != 'OFFLINE';
TABLESPACE_NAME STATUS SEGMENT_NAME ------------------------------ ---------------- ------------------------------ SYSTEM ONLINE SYSTEM APPS_UNDO NEEDS RECOVERY _SYSSMU77$
I'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.
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.
Operating 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.
we have a situation where both undo tablespaces were almost filled i.e UNDOTBS1 99% and UNDOTBS2 100% filled so i add data files to it and then i found a lot of blocking session and was just killing them through EM then i stop my front end listener and also down the service, now i don't have any blocking session but on EM a big WAIT is coming. alert log shows nothing serious, it was showing deadlock but now it is over as well.
I have a serious doubt in oracle architecture functionality, when a user issues a update statement the data blocks are carried to db buffer cache and where does the changes to the data blocks are made???? Does a copy of the data block is kept in db buffer cache and the changes are made to the block in buffer cache?? or the a copy of the data block is kept in undo tablespace and changes are made to the blocks in the undo tablespace???
In simple the changes to the data blocks are made at db buffer cache or undo tablespace?
i'm facing a problem while i'm inserting millions of record from table to table that undo tablespace reach 100% full and execution aborted. , how can free the undo tablespace ??? many of extendes are offline. will it flush automatically ??? or what i should do