Getting hold with Oracle Database 11gR2 RAC

Oracle Database 11gR2 MOS Notes Doc ID 1232802.1 RAC One — Changes in 11.2.0.2 Doc ID 1312225.1 Things to Consider Before Upgrade to 11.2.0.2 Grid Infrastructure Doc ID 1267828.1 SYS Password Management with RAC and Data Guard Doc ID 1276368.1 Complete checklist for out-of-place manual upgrade from 11.2.0.1 to 11.2.0.2 Doc ID 341880.1 How to […]

Read the rest of this entry »

Oracle Hanganalyze Performance Problems “sqlplus -prelim”

Hanganalyze / Librarycache contention Last week I was called up to  help to resolve one of the production database hung issue. This totally screwed the database by all means  [ Database connections were hanging, Connections on the server using SQL*Plus as sysdba was also hanging, EM grid was spinning ] Dammn totally stuck …. you […]

Read the rest of this entry »

Oracle 11g New Feature Causes AMM to Restart

This post is from one of the emails I have recieved from my friend Mackenzie D’Cruz, he experienced this issue on his production environment. This information is published by Don Burleson at http://www.dba-oracle.com. So this is just a copy to let our readers know about this issue. Beware, following new upgrades to 11gR2, you can […]

Read the rest of this entry »

Oracle DBA Silver Bullets – Performance Queries

Just thought to share few queries from my repository. It may be useful for all new DBAs. Of course these are quite old ones and you can do most of them through Enterprise Manager, still we DBAs always like command line 🙂 Show sessions that are blocking each other : select ‘SID ‘ || l1.sid […]

Read the rest of this entry »

Oracle 8i to 11g – hidden features.

Every release contains many new features and enhancements that are not highlighted in the marketing material. Oracle assumes all customers will move on to new versions when they are released. Here are few examples of those – New  features failed to spot. DBMS_SYSTEM.KSDWRT undocumented package installed in all databases Used to write messages to trace […]

Read the rest of this entry »

Real Application Testing Oracle RAT 11g

What is the critical concern when we need to make a change in the production database ?  The biggest concern is the risk of the change – “mess up” something. Even the most minor changes can have an awful effect, eventually producing a visible impact. In Oracle Database 11g, We have a new feature called […]

Read the rest of this entry »

How to change ASM SYS Password and Creating SYSASM user 11g.

Things tried: SQL> select INSTANCE_NAME from v$instance; INSTANCE_NAME —————- +ASM SQL> ALTER USER sys IDENTIFIED BY <new_password> REPLACE <old_password>; ALTER USER sys IDENTIFIED BY <new_password> REPLACE <old_password> * ERROR at line 1: ORA-01109: database not open We can not change the password for ASM databases via alter user command.Because passwords are managed through password file […]

Read the rest of this entry »

Certification – Oracle Database 11g New Features for Administrator 1Z0-050

Are you Oracle 10g OCP ? Then its time to upgrade for 11g OCP. Its very easy, focus on 11g new features – you can refer to Arup Nanda’s top new features white paper from Oracle web site also go through bellow questions, these are 100% sure questions repeated in all exams. QUESTION 1 Identify […]

Read the rest of this entry »

Oracle Performance Tuning – How to Use AWR ?

Here are few silver bullets to use AWR for diagnosing performance issues ….. AWR – Automatic Workload Repository Detailed & comprehensive performance history Based on “snapshot” (time interval) Automatic Database Diagnostic Monitor (ADDM) About 79 DBA_HIST_* “tables” Defaults: Hourly snapshots Weekly retention (month is better) Overview of important AWR tables DBA_HIST_SNAPSHOT PK: SNAP_ID DBID, INSTANCE_NUMBER […]

Read the rest of this entry »

DB Console issue after cloning 11.5.10.2 environment

DB Console issue after cloning 11.5.10.2 environment Issue: – 1 — On Applications 11.5.10.2 with RDBMS 11.1.0.7: After cloning dbconsole cannot start. When Checking the $ORACLE_HOME/bin directory and the following emagent, emdctl programs are missing. Step by Step Solution to start and discover DB target to DB Console in Stat and elabs Environments: 1)     Source […]

Read the rest of this entry »

Tuning High CPU Consumption on Oracle server

For any performance tuning issue, our strategy in diagnosing the problem is to take a “top-down” approach and follow the trail of highest CPU consumption down to the offending processes, and eventually the offending sessions and query. Verify CPU Consumption on the server is the first step any DBA should do for a top-down approach […]

Read the rest of this entry »

Tuning indexes on RAC environments-4

Excessive undo block shipment and contention for undo buffers I have seen this scenario in one my projects where  Oracle EBS workload is high. When a select statement needs to read a block with active transactions, it has to cleanout the block and undo the changes to create a CR version. If the active transactions […]

Read the rest of this entry »