I’m an experienced Oracle Applications DBA with more than a decade of full-time DBA experience. I have gained a wide knowledge of the Oracle software stack and have worked on several big projects for multi-national companies. I enjoy working with the leading-edge technology and have passion for database performance and stability. Thankfully my work allows me time for researching new technologies (and to write about them).
OEM 13c (13.2) has many new features which make this version more useful than the previous OEM versions. If you are moving from OEM 12c to OEM 13c first change you will find will be that the appearance and look and feel of application is change a lot. In the starting you may feel little overwhelmed as you may be working for long in OEM 13c and may have got accustomed to it.
Some of the noteworthy new features of OEM 13.2 are mentioned below:
1. ENHANCED SUPPORT FOR VIRTUALIZATION SOFTWARES
Oracle VM enables virtual machines to be deployed, managed, and moved throughout Oracle’s public and private cloud infrastructure. Oracle Enterprise Manager 13c can manage Oracle VM technologies efficiently. The Enterprise Manager for Oracle Virtualization (VT) Plug-in has been extended to work seamlessly with Oracle’s latest server virtualization product, Oracle VM Release 3.4
OEM tool has improved a lot in last decade. Oracle has added so many new features to it and fixed many software bugs. In coming years OEM will prove more important as the OEM capabilities are constantly increasing and the increasing trend of Hybrid setups (cloud and non-cloud) requires some monitoring tool which successfully monitors all kind of setups.
This post will describes some noteworthy capabilities of OEM and what all you can achieve by using OEM with your technological setups.
Oracle Enterprise Manager is Oracle’s solution to manage/monitor various database/applications which may be running on Cloud infrastructure or on-premise. OEM 13c is the latest version at the time of writing this post. In this post we will discuss about the architectural components which are required by Oracle Enterprise Manager.
Below is simple architectural representations of an OEM 13c setup.
The active session history (ASH) sampler performs the sampling. ASH samples the current state of all active sessions. The database collects this data into memory, where you can access it with a V$ view.
Using ASH enables you to examine and perform detailed analysis on both current data in the V$ACTIVE_SESSION_HISTORY view and historical data in the DBA_HIST_ACTIVE_SESS_HISTORY view, often avoiding the need to replay the workload to gather additional performance tracing information.
ASH also contains execution plan information for each captured SQL statement. You can use this information to identify which part of SQL execution contributed most to the SQL elapsed time. The data present in ASH can be rolled up on various dimensions that it captures, including the following:
The Automatic Workload Repository (AWR) automatically persists the cumulative and delta values for most of the statistics at all levels except the session level.
This process is repeated on a regular time period and the result is called an AWR snapshot. The delta values captured by the snapshot represent the changes for each statistic over the time period.
The Automatic Workload Repository (AWR) collects, processes, and maintains performance statistics for problem detection and self-tuning purposes. This data is both in memory and stored in the database.
You can utilize Oracle Database dynamic performance views to query important tuning related parameters like memory utilization, Disk I/O, Disk structure etc. These dynamic performance views are special views that are continuously updated while a database is open and in use.
Note that the actual dynamic performance views are identified by the prefix V_$. Public synonyms for these views have the prefix V$. You should access only the V$ objects, not the V_$ objects.
In our EBS system, we found that SYSADMIN login was slow. It was taking around 4-5 minutes to login and when inside the EBS application it was taking 2-3 minutes every time we were navigating in the self-service pages. This issue was not occurring for normal EBS users. We thought of applying the trace to SYSADMIN user to find the root cause of it.
Keeping data secure is one of the primary job of DBA. Oracle’s Transparent Data Encryption Tablespace Encryption option of Oracle Database 11g Enterprise Edition provides an excellent method to encrypt data at rest. This option works perfectly with Oracle EBS R12.
The TDE Tablespace Encryption option can be used to encrypt the tablespaces that store the content of your E-Business Suite application so you can encrypt the database files and any backups of these files. Good thing about TDE is you do not have to change any of your existing code as TDE is transparent to application.
A well-planned methodology is the key to success in performance tuning. Without a proper diagnosis of the issue any troubleshooting step taken will further delay the resolution. Example, a DBA can not just blindly start tracing/tuning a SQL/Sessions when all symptoms on careful analysis points towards issues with DIsk/Memory/Network etc.