System Hardware

Hopefully you were given the chance to complete the configuration analysis discussed previously before the final hardware configuration was established for your new database server. However, if the box were purchased long before the Oracle software and documentation arrived, you would not be the first person who had to try to make do with a system that was not optimized for the Oracle database envisioned for it. However, if you do have the option, I would like to present you with a few considerations:

•  Oracle runs on a number of platforms; however, the support for some platforms is better than the support for others. If you are trying to implement a mission critical system or large system, you will probably be very interested in having the latest updates to the Oracle database management system. Hence, you may want to stick to a tier-one platform (Sun, HPUX, AIX, Windows NT, and the other platforms Oracle develops and releases its products on first). There are some platforms that are supported (for example, Data General UNIX), but may not have all of the additional products that you desire or that are several revisions behind the others.

•  Consider some form of disk mirroring or RAID (redundant array of inexpensive disks). While Oracle provides facilities to recover from a failed disk drive, it is much better for production if you can keep going while the technicians are on their way to fix the problem. Disk prices are relatively low and this is a good use of funds for important production systems.

•  Be conservative on your memory estimates (get a little more than you need). Memory is also relatively inexpensive these days and with Oracle, memory is speed. You may find that you need to increase some of the memory areas over your calculations as the database grows in popularity. If you do not want to buy the memory at the start, at least make sure the computer memory can be easily expanded.

Software Module Planning

Another checklist that you will work through as part of your installation planning is building the list of software options that you want to install. Depending on what you purchase, you may be licensed for several of the optional modules that make up the Oracle database. What I wanted to stress here is that you include these modules as part of your plan when determining the disk and memory space required on your system. Some of these modules (that is, those involved with video) can also provide performance stresses on lesser computer systems (disk transfer, network transfer, and CPU), so be sure that you have done your homework to ensure that your system is up to the tasks. How? My favorite method is to ask the salesman for test results or references of similar customers. It is worth the time talking to a few people before you try to implement an impossible solution.

Optimal Flexible Architecture (OFA)

When I installed my first Oracle version 6 database, the documentation told me that I needed places to put my software and data. It did not provide any real, clear guidance as to how to arrange my files in a manner that would promote growth in data and software upgrades. Many people installed their systems only to realize that they had to do a lot of rearranging when it was time to grow. To address this problem, the folks at Oracle’s consulting arm got together and came up with the Optimal Flexible Architecture (OFA). Recall that it is a recommended architecture for locating information on disks. Figure 5.3 illustrates the portions of this architecture that are applicable to Oracle installations.

Figure 5.3.  Oracle’s Optimal Flexible Architecture (OFA).

With OFA, you allocate a directory that is referred to as the ORACLE HOME (in UNIX, it is stored as the environmental variable ORACLE_HOME). This directory is placed somewhere in the array of disks that matches your other goals. Some versions of the Oracle installation guides recommend placing it under the user home directories. Later versions, however, place it on an applications disk drive that your system administrator allocates for you.

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NOTE:  
I strongly agree with the idea of using a separate applications disk, because newer releases of the software consume a great deal of disk space and user home data disks are notorious for filling up rapidly. This causes problems when Oracle needs to write an error log file and finds that the disk is full because Charlie insists on keeping 25 versions of all software that he writes.

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