Microsoft Windows NT Configurations

Who cares about Microsoft and Windows? Oracle for one. Almost every day, Oracle representatives take swipes at Microsoft, DCOM, SQL*Server, and Visual J++. Many UNIX loyalists will claim that Windows NT is just a fad and that UNIX will eventually rule the day. However, Oracle is not betting on this. Last year, Oracle made Windows NT a tier 1 platform. This means that Windows NT is one of the few operating systems to which new Oracle server products are ported. Recently, that status has been upgraded so that Windows NT is now sharing the title of reference port with Sun Solaris. What this means is that when Oracle develops server products, they are developed on both Solaris and NT at the same time. The Solaris version is then ported to other UNIX variants.

Hopefully by now you are convinced that Oracle is serious about Windows NT. There are several advantages to this version of the Oracle server products that you might want to consider:

•  You do not have to relink object modules when you install the software as you would under UNIX. Due to the standards imposed by Intel and Microsoft, you are able to load directly executable software (that is, .exe and .dll files). This prevents anomalies in various versions of the UNIX operating system from making it long or difficult to complete the Oracle installation.

•  Due to the use of the Registry, Oracle is much more aware of the operating system and Oracle environment. This means that it is less dependent on which environmental variables you have set up to determine installation parameters. It may not seem like much, but it can save a lot of time fussing over getting the environment set up correctly for your installation.

•  You can install the DBMS software and have a working database in less than 30 minutes.

•  Because a graphical user interface is presumed with Windows NT, Oracle can implement a full graphical tool set to control and interact with the database under NT. It does not need to have a character-based tool set to accommodate users who telnet into the server (telnet support is an optional third-party product under NT).

Of course, there are a few disadvantages to Windows NT from an Oracle perspective. I actually split my time fairly evenly between NT and UNIX versions of Oracle, so I feel compelled to list the following disadvantages of the Windows NT version of Oracle when compared with the UNIX varieties:

•  Windows NT does not scale up to support as large a number of CPUs. This limits the overall processing capabilities of an NT Oracle database when compared to very large multiprocessor configurations running UNIX (which make up a small percentage of the total number of Oracle databases out there today).

•  Windows NT does not support as much disk storage. If your database is on the order of terabytes, you will probably be looking to large UNIX multiprocessors to support this load.

•  Windows NT does not support a number of different versions of Oracle installed on the same system. You can have multiple instances on the same NT server if they are running the same version of the DBMS. The NT philosophy for Oracle is that because you can buy a relatively cheap development and test computer, run your tests on a separate computer. I actually prefer this philosophy in that I do not want development and test going on anywhere near my production databases.

Oracle8 Under Windows NT

One of the first things that you would notice under a Windows NT installation of the Oracle DBMS is that you cannot find the familiar processes that are described previously in this chapter. They are functionally still there and operating, it is just that Windows NT is not designed to be a collage of a large number of background processes. Instead, background processes are organized into what Windows NT designers refer to as services. Each of these services can have a number of threads associated with them representing what would be considered background processes in an operating system such as UNIX. The NT operating system gives designers incentives to group threads together into services by providing enhanced interprocess communications mechanisms within the service. Under Windows NT, you would have the following services:

•  Oracle start service for each instance. This service is used to start the main Oracle DBMS service. The two are tied together so that when you start the Oracle start service, the main DBMS service is started without user intervention.

•  Oracle service for each instance. This service encompasses the main database processing functions described previously (database writing, log writing, process monitoring, and system monitoring).

•  Oracle Net8 or SQL*Net listeners. These services monitor communications via SQL*Net or Net8 and transfer information between the network and the DBMS.

Summary

This chapter has provided an overview of the architecture of the Oracle8 DBMS. This system can be thought of as a collection of background processes, memory areas, and data files. Together, they provide an environment that takes care of the details of data storage freeing the developer to concentrate on the business needs of an application. There are several options and variations to this architecture that accommodate specific computer environments. However, the beauty of these implementations is that the system remains pretty much the same on a conceptual basis.

In Part II, “Installation, Upgrade, and Migration,” I will cover the components of the Oracle8 system in much greater detail. This information can be useful when you are trying to push the envelope of performance on your system. Only when you fully understand what is happening can you use the system to your advantage.