While at the conference, an interesting statement stuck with me. In a presentation on configuring Oracle Portal in Oracle Application Server 10g (don’t call it 10gAS), the presenter said, “Enterprise Manager is a wonderful tool for managing and monitoring Oracle 10g – database and application server.”

Now, this stuck with me for a couple of reasons – first, the rest of the presentation did not provide me with much new information; and, second, I was never a big fan of Enterprise Manager (EM); in fact, I am always telling my students and clients to learn the command line because it always works and is usually quicker than some GUI.

So, what did this guy know that I didn’t? I set out to discover.

The Ugly Duckling
The first release of Oracle Enterprise Manager (OEM) that I ran across was shipped with Oracle 7.3 many years ago. It was a slow, Windows-based application using Java and taking up way too many resources. Better still, if you used the right tools in the right order you would be greeted with a wonderful result -- the whole thing would hang and be almost impossible to kill. Trying to have multiple users manage multiple databases across different platforms required convulsions on each server to get the Oracle Agent to work and a separate OEM repository for each manager. This meant that you could have as much space used by the repositories as your data held. O.K., I exaggerate, but the point is that it was not easy. Oracle’s licensing scheme for the initial release of EM was clear to no one, including Oracle sales reps, so nobody really bought into the concept -- I certainly did not.

The Swan Begins To Emerge
With the release of OEM 1.2 things got a little better. The crashing was less frequent (though it still happened when you did not want it to). The architecture changed so that a central repository for all users could be configured and permissions assigned to different OEM users. The job and event system were more refined and allowed for e-mail notification of problems and job results (it was there before but I could never get it to work). Oracle Agent was more stable on all platforms and communication between the Management Server and agents was less problematic. OEM 1.2 was still a Windows-based application written in Java, and it was a pig to run.

Oracle updated OEM with the release of Oracle 9i and its associated products – 9iAS, Portal, etc. – as well as Oracle eBusiness Suite. Oracle eBusiness Suite also included Oracle Application Manager, a Web-based tool to manage and configure portions of this expensive ERP product. Oracle 9i also saw a Web-based implementation of OEM that was handy in managing Real Application Clusters (RAC) and allowed monitoring of the Oracle instance. The problem with OEM (now re-branded to just plain Enterprise Manager, or EM) in Oracle 9i¸ even though it was Web-based, is that it was still a resource hog. Unless you had really fast hardware and gobs of RAM, navigating from one page to another using the Web-based interface took a very long time.

The Swan Arrives – with Brawn to Boot!
Enterprise Manager in Oracle 10g has solved two of the main problems I had with previous releases: speed and power. On the speed front I was absolutely flabbergasted that with all the new features the navigation between pages was still much quicker than in previous releases. Furthermore, the ability to monitor, manage and automate administration of Oracle databases and application servers is far in excess of anything seen from Oracle to date. A real impressive component of EM is the Grid Control, which allows me to monitor multiple databases, application servers, host computers, and other components and configure rules by which allocation of resources to different parts of my Oracle infrastructure can be dynamically performed by EM. Furthermore, EM monitors itself and will restart failed components automatically to ensure that your management framework in not compromised.

That’s Nice….but How Does It Work?
The first thing you will notice about EM for 10g is that it is installed automatically when you pick the typical install of Oracle 10g database or application server. Although though there is still a fat client version of EM (if you want to use it), EM now is primarily a purely Web-based interface, allowing you to manage a single database instance through the use of a Database Control. If you want to monitor more than one database instance, you will need to install the separate Grid Control which can provide a single seamless interface for all databases, application servers, hosts and other Oracle components. I still need to play some more with the Grid Control, but the Database Control by itself is impressive.

You can access the EM Web console page by using a browser and pointing it to the URL and port number provided by the install program (http://:5500/em by default for a Database Control install). When you do so, you will be presented with information on the database you are managing, as well as monitoring details such as memory utilization, CPU utilization, any alerts for thresholds that have been exceeded, and the ability to configure its components such as INIT.ORA parameters, tablespaces, undo segments, users and much more.

One feature that I was very impressed with is the ability to configure EM to connect to Oracle MetaLink and determine whether any patches are required for the current instance. You can then have these patches installed automatically or have them downloaded so that you can test and deploy them later. With the Grid Control you can configure monitoring of patches for deployment of different Oracle versions under the control of EM. These can then be downloaded, tested on one instance, and, if things work out O.K., rolled out to others.

It gets even better. Most organizations will have copies of the production database or application server for development and/or testing. With EM, you can now easily clone an Oracle 10g database or application server from within EM and then deploy it on another host, or create a copy with a different instance name on the same host. Sadly, this only works for Oracle 10g databases, so you will need to upgrade before you can make use of it.

Monitoring database and application performance is one of the key features of EM in the latest release of Oracle and it does this very well. You can monitor both database performance as well as the performance of the application server (again, 10g versions have the best information). You can set thresholds for performance of things such as page load times and then have appropriate corrective actions take place when those thresholds are reached or exceeded. Notification of these events taking place is also integrated. To boot, you can monitor database and application performance using a PocketPC device with EM2Go.

Tempted, but Not Letting Go…
I could go on and one, but suffice it to say that EM in Oracle 10g is the first release of a GUI tool from Oracle that I have been excited about. I plan on using it a lot more, but will always go back to SQL*Plus and the command line -- I can’t get rusty or my clients and students may wonder if I have forsaken the command line for a prettier alternative. My affair with the brawny swan that is EM will need to be somewhat secretive.

But I do have to admit ...I was wrong about EM!