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?
I 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?
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.
The undo_retention is used for read consistency, to avoid snapshot too old.Flashback database is using files in the db_recovery_file_dest.But whether undo_retention has any influence on Flashback drop; Flashback table or Flashback query?Let's say we have set undo_retention = 3600 = 1 hour.And
db_flashback_retention_target = 1440 = 24 hours.
Will it work Flashback drop; Flashback table; Flashback query to get 12 hours back?Additional question. Why Oracle sets undo_retention in seconds and db_flashback_retention_target in minutes?To use the same measure would be more user-friendly to DBAs .
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
Step 1: Increased Physical Memory on one Node from 32 G to 48 G. Step 1 Impact : DB was running same as before Step 2 : Increased SGA from 12 G to 15 G. Step2 Impact : DB was running same as before for 1 day next day one reporting job was hanging. Step 3 : Increased DB_CACHE_SIZE from 5G to 7G. Step 3 Impact : Over all CPU Utilization was high and no effect on reporting job. Step 4 : Decreased DB_CACHE_SIZE from 7 G to 5 G. Step 4 Impact : CPU Utilization came down little bit but no effect on reporting job.
Now our main concern is why CPU Utilization is going high. Because same thing we did last time and we got positive results.
NAME TYPE VALUE ------------------------------------ ----------- ------------------------------ lock_sga boolean FALSE pre_page_sga boolean FALSE sga_max_size big integer 1152M sga_target big integer 0
[code]....
in scenario above, the database do not using ASMM, and spfile If I wan to increase db_cache_size parameter, do i need to rebounce instance?
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 am running Oracle 10.2.0.1.0 on MS Windows 2003 server 64-bit with 16G RAM.
Here is the findings for my Oracle database.
SQL> select * * from v$sgainfo; NAME BYTES RES -------------------------------- ---------- --- Fixed SGA Size 1293560 No Redo Buffers 7094272 No Buffer Cache Size 830472192 Yes
[code]...
I find that the SGA component "Buffer Cache" is decreasing from the start "1.8G" and down to now 0.8G. On the other hand, the component "Shared Pool" is increasing from the start 0.3G to now 1.2G. I noticed that there are 100 operations of shrinking of "Buffer cache" and growth of "Shared Pool" in Oracle every day.Is it a indicator that I should raise up the SGA_MAX_SIZE?
I tried to increase the SGA_MAX_SIZE to 4G. But I cannot start the Oracle afterward.Is it a limitation of MS Windows(OS) or Oracle?I set the SGA_MAX_SIZE to 3G. This time, I can startup Oracle.What is the optimum/maximum I can set to SGA_MAX_SIZE?Is there any adverse effect/concern when setting the SGA_MAX_SIZE more than 2G?
Objective : To find solution to archieve data from 2 big tables which is occupying maximum size in the data base. With current data (From Jan 2005 to Sept 2011) it has records as mentioned below:
We need to load data and run monthly batches from October 2011 to current month which will increase this space.
1. Issue is there will not be having so much space.
2. Maintenance of such table is diffcult now.Also there is huge impact on performance. Can we think of partitioning the table base on date aswe query 1st table based on certain date range?
3. Most of reports use this table and creating performances issues
The REDO log file size is important DB performance issues when DB is run archivelog mode.If DB run noarchivelog mode, REDO log file size not impact to DB performance.
I would like to make a change on the live system!I have read a book and found a information about REDO log file size is impact on DB performance.My DB current log file size is 100 MB. But, Oracle 10g's Redo Logfile Sizing Advisor offer the optimal log file size is 1845 MB.What REDO log file size is best for my Oracle database?
All the analysis till now on our system proves that our system is clearly I/O bound and db sequential read is the biggest culprit.
We have even identified the index which is being affected by sequential read. I am thinking of creating a new tablespace with 32K blocksize (currently all table spaces are 8k) and migrate this index to the new space. That way, Oracle will have to do less number of reads to get the required data.
But is there anything wrong in having just one tablespace with a differnt block size? Or is there anything that I have to be watchful about while doing it?
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?.
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]..........
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'?
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 ?
