How to remove OEM agent in the release 3 of the Oracle Enterprise Manager.

OEM 12c R3 has a very useful Perl script which allows removing an installed OEM agent in the host. The process is quite straightforward just by invoking the AgentDeinstall.pl script located under:$AGENT_HOME/sysman/install/AgentDeinstall.pl[oracle@ol6-112 12.1.0.3.0]$ /u01/app/oracle/agent12cr3/core/12.1.0.3.0/perl/bin/perl /u01/app/oracle/agent12cr3/core/12.1.0.3.0/sysman/install/AgentDeinstall.pl -agentHome $AGENT_HOME  Agent Oracle Home: /u01/app/oracle/agent12cr3/core/12.1.0.3.0NOTE: The agent base directory: /u01/app/oracle/agent12cr3 will be removed after successful deinstallation of agent home. DetachHome… Continue reading How to remove OEM agent in the release 3 of the Oracle Enterprise Manager.

Oracle Enterprise Manager 12c Release 3 New Features

Today I will talk about some new features in the release 3 of the Oracle Enterprise Manager. All Metrics Chart EnhancementsThis new feature show more data in the metrics page, like minimum and maximum values, it will highlight periods when the agent was unreachable or target was down, it will also show the period when… Continue reading Oracle Enterprise Manager 12c Release 3 New Features

Understanding Oracle Histograms

Histograms are a feature of the Cost Based Optimizer (CBO) that helps to know the data distribution in a column. Histograms should be created in columns with highly skew data and are included in the filter clause (WHERE) of a SQL statement.Histograms play a very important role in the creation of the execution plan and… Continue reading Understanding Oracle Histograms

MRP0: Background Media Recovery terminated with error 1237

Some days back checking an Oracle physical standby database found that the DB was some hours back than the primary database.alter session set nls_date_format='DD-MM-yyyy HH24:MI:SS';show parameter destselect thread#,max(sequence#) from gv$log_history group by thread#;select (a.amct-b.bmct)*24 "Hours Standby is Behind: " from (select max(completion_time) amct from v$archived_log) a, (select max(completion_time) bmct from v$archived_log where applied='YES') b;Hours Standby… Continue reading MRP0: Background Media Recovery terminated with error 1237

Testing user calls

In the performance tuning world specially talking about Response Time Analysis (RTA), user calls is often used as a workload metric; however this instance statistic was not yet completely clear.When this metric is incremented?, How this metric is instrumented?, Why sometimes user calls is less with the same SQL statement?; these were some questions rounding… Continue reading Testing user calls

Oracle 12c ASM new features

Today I will talk about some new features for ASM on 12c version.Oracle Flex ASMOracle Flex ASM is a set of new features that provide critical capabilities required for cloud computing. Oracle Flex ASM redefines the traditional ASM cluster architecture of having one ASM instance on every node in the cluster; this means you can… Continue reading Oracle 12c ASM new features

Why my new Disk Group is not getting mounted automatically when ASM instance starts?

Today I faced the issue that a new ASM Disk Group created in instance +ASM1 is not getting automatically mounted in instance +ASM2.The first step was to check DB dependencies:[oracle@ol5-112-rac2 trace]$ srvctl config database -d RACDatabase unique name: RACDatabase name: RACOracle home: /u01/app/oracle/product/11.2.0/db_1Oracle user: oracleSpfile: +DATA/RAC/spfileRAC.oraDomain: localdomainStart options: openStop options: immediateDatabase role: PRIMARYManagement policy: AUTOMATICServer… Continue reading Why my new Disk Group is not getting mounted automatically when ASM instance starts?

ORA-15097: cannot SHUTDOWN ASM instance with connected client

In 11g R2 Clusterware configurations the OCR is located in ASM disk, that’s why ASM can’t be shutdown while the cluster is running.  You have to shutdown your cluster in order to shutdown ASM instance.Oracle support note 984663.1Here’s a good blog about this:http://divakarmehta.wordpress.com/2012/04/19/how-crs-accesses-ocr-in-oracle-asm-during-11-2-grid-infra-rac-startup/Example, how to shutdown ASM instance on node ol5-112-rac1:[oracle@ol5-112-rac1 ~]$ crsctl status resource -t--------------------------------------------------------------------------------NAME           TARGET … Continue reading ORA-15097: cannot SHUTDOWN ASM instance with connected client

GoldenGate 11G Install on Linux x86

Today I will show you how to install GoldenGate under Linux 5.5 following the recipe of my teammate Gleb.(http://www.pythian.com/blog/oracle-goldengate-installation-part-1/)Prerequisites:·          Oracle Linux 5.5 installed in 2 VM using VirtualBox, I have used one pre-built VM from Oracle (http://www.oracle.com/technetwork/database/enterprise-edition/databaseappdev-vm-161299.html)·          Download Oracle GoldenGate software from (http://www.oracle.com/technetwork/middleware/goldengate/downloads/index.html)·          Start both VM machines and change the host name to source_host &… Continue reading GoldenGate 11G Install on Linux x86