An Overview of Database Design
    Databases are the heart of the Expert Help Hypertext System. Almost all
    of the information you see in the display window (from pull-down menus
    to Related Topics) is stored in the database file. The Database Composer
    also puts additional information into the database to speed up the access
    to the data.

    Pull-Down Menus
    Pull-down menus (defined by the author of the database) provide the
    basic structure of database. Expert Help databases contain a number of
    separate, but still related, sections of data. Each of these sections
    is accessed through an item in a pull-down  menu. This makes it easy to
    pinpoint the data you want, or just browse through the data when you're
    not sure what you're looking for.

    The advantage of menus is that they provide a fairly "flat" database
    where short entries (which you can think of as a table of contents)
    expand to longer descriptions.

    It is possible to build tree structures, where entries in a list are
    Expanded into other lists of short entries (sort of like having a book
    within a book). Expert Help's Global Search capabilities make finding
    this "tree structured" information painless.

    Entries
    All the data in a Hypertext Database is organized as one of two
    structures: short entries and long entries. Short entries are
    one-line descriptions that serve as pointers to more complete
    descriptions. Those complete descriptions are called long entries.

    When you select Expand, you are asking to view the long entry
    pointed to by a short entry. A short entry can and usually does
    expand (point) to a long entry. Alternatively, a short entry can
    expand to a list of short entries, creating a "deeper" database.


    Data Text Files
    Each item in a pull-down menu points to a separate section of the
    database. And each of those sections is created as a separate data
    text file. In other words, you will have at least one data text file
    for each menu item. (You can also use the !file command to build
    deeper, more complicated structures - in which case, you will create
    more than one source file per menu item.)

    As mentioned above, data text files are comprised of short and long
    entries. A single text file can contain either a list of short
    entries, with their long entries directly underneath, or a single
    long entry.

    The Database Composer - (A Compiling and Linking Overview)
    At this point you may be wondering how all of these text files are
    transformed into a single Hypertext Database. That's the function of
    the Database Composer's Compiler and Menu Linker. The Composer compiles
    and links your text files into a finished Database, complete with
    your data, information about menus and menu names, and special informa-
    tion (included by the Database Composer) to speed access to your data.


    From Text Files to Finished Database
    After creating the text files, you need to compile them. The Database
    Composer builds intermediate files, which the Menu Linker uses to build
    the finished database. These intermediate (or object) files have the
    extension .EHO.

    The last step in creating a database is linking the compiled
    (intermediate) files together using the Database Composer's menu
    linker. Linking produces a single file compatible with the Search
    Engine. Linking is also the point at which the menu structure of
    the database is defined. The menu structure is defined by a text
    file called the menu link control file, which the Database Composer
    uses as a template for the finished database. The Database Composer
    combines the menu information from this file with the data from the
    (intermediate) object files to create a finished Hypertext Database.

    Here is a summary of the steps for creating a Hypertext Database:

             1. Create text files with your data.

             2. Compile each text file with the Database Composer.

             3. Create the menu link control file, which
                defines the menu structure of your database.

             4. Link the files with the Database Composer's Menu Linker.

             5. Access the new database with the Expert Help Engine
                and review the layout of your information.




    Press the Gray + key to proceed to the next topic (long entry).