The categories you choose for your database will vary, however, depending on what resources your Compass Server indexes. For example, a very broad index, such as an Internet directory, might choose to categorize documents by general areas of knowledge, such as science, art, business, and so on. Each of those areas could in turn be subdivided into more specific categories. But the highest-level categories could just as easily be geographical, with each geographical division subdivided in various ways.
No matter what the scope of the index you design, the primary concern in setting up your categories should be usability. That is, you need to know how users will use the categories. For example, if you were designing an index for a company that has three main offices in different locations, you might make your top-level categories correspond to each of the three offices. But if users are more interested in, say, functional divisions that cut across the geographical boundaries, it might make more sense to categorize resources by corporate divisions.