By Francisco Munoz Alvarez How to find Sessions Generating Lots of Redo To find sessions generating lots of redo, you can use either of the following methods. Both methods examine the amount of undo generated. When a transaction generates undo, it will automatically generate redo as well. The methods are: 1) Query V$SESS_IO. This view…
Category: Questions
Are you having problems with the OEM Host Credential?
If you are using LINUX/Windows the hostname credentials should be the same user who has installed the oracle database software, if Windows the user you are using need to be member of the ORA_DBA group and have Local Security privilege ‘Log on as a batch job’. What you need to do is go to: Start—->…
How to find all user Roles and Privileges?
Here is the scripts to help you to get this information: PROMPT PROMPT PROMPT ******************************************** ROLES AND PRIVILEGES PROMPT PROMPT ******************************************** USER ROLES SELECT grantee user, granted_role, admin_option, default_role FROM dba_role_privs WHERE grantee IN (SELECT username FROM dba_users) AND grantee NOT LIKE ‘%SYS%’ AND grantee NOT IN (‘DBSNMP’,‘OUTLN’) ORDER BY grantee; PROMPT PROMPT ******************************************** USER…
How to migrate from 32 bit to 64 bit using RMAN?
This procedure can be used for single instance or RAC (9i to 11g): In the 32 bit source server : Start making a full backup of the database including all archivelogs: RMAN> run { allocate channel c1 type disk; allocate channel c2 type disk; backup database plus archivelog; backup current controlfile; } In the target 64 bit server:1)…
How to Start and Stop a RAC Environment
Auto Start/Stop The Oracle Cluster Services handle the automatic start and stop of the Cluster, Listener, ASM and the Database. For the Grid Control Agent, the auto start- stop is handled via the /etc/init.d/dbora script. On server boot the dbora script starts the agent with /home/oracle/scripts/start_agent. On server shutdown the dbora script calls /home/oracle/scripts/stop_agent Manual…
How can I start a trace?
Here are some possible ways to setup Trace: To Enable trace at instance level 1) Set the parameter sql_trace in the pfile or spfile. It will enable trace for all sessions and the background processes sql_trace = TRUE to enable it or to disable trace use sql_trace = FALSE 2)To enable tracing without restarting the…
How to setup a Basic Audit?
For any Oracle versions prior to 9i you will need to set audit_trail parameter in the pfile ie.g.: audit_trail = DB For later Oracle Versions: SQL>alter system set audit_trail = DB; To enable auditing for a specific object run the following command: SQL>AUDIT SELECT, INSERT, UPDATE, DELETE ON SCHEMA.TABLE; To stop auditing use: SQL>NOAUDIT SELECT,…
Differences between UNDO and REDO
To clear this question we have this table: UNDO REDO Record of How to undo a change How to reproduce a change Used for Rollback, Read-Consistency Rolling forward DB Changes Stored in Undo segments Redo log files Protect Against Inconsistent reads in multiuser systems Data loss UNDO Undo tablespaces are special tablespaces used solely for…
What is the difference between Rollback and Undo Tablespace? OTN Forum By user user503050
There might be confusion while undo and rollback segment terms are used interchangeably in db world. It is due to the compatibility issue of oracle. Undo Oracle Database must have a method of maintaining information that is used to roll back, or undo, changes to the database. Such information consists of records of the actions…
EM mess – by Slyt – OTN Forum
I tried to run EM on certain host: [oracle@SQLAB db10g]$ emctl dbconsole start TZ set to Poland EM Configuration issue. /u01/app/oracle/product/10.2.0/db10g/SQLAB_e2k not found. OK. No such dir indeed. So: [oracle@SQLAB db10g]$ emca -config dbcontrol db -repos createblablabla Do you wish to continue? [yes(Y)/no(N)]: Y 2008-06-19 13:12:12 oracle.sysman.emcp.EMConfig perform INFO: This operation is being logged at…