Compiling a Data Base Definition

Once a DBD is entered and saved, it is "compiled." The compile process analyzes the DBD text and creates the files that house the actual database.

There are three ways to compile a Database Definition.

First, from the File menu, select Data Base Definition and you get the DBD listpick dialog:

Select a DBD from the list and click on the "Compile" button.

Second, if you have the definition up and are looking at it (be sure you have saved any changes you may have made) you can press the Compile button on the toolbar:

Third, you can compile from the command line via the DBD COMP command.


Compiling

The DBD document is the source. The outputs from the compile process are:

                                XXXXXXXX.ctl                   Control space
                                XXXXXXXX.ddd                Data space
                                XXXXXXXX.ttt                   Structure space - trees
                                XXXXXXXX.lll                    Structure space - lists
                                XXXXXXXX.mmm              Memo field space (if DBD has memo fields)
                                XXXXXXXX.sss                 Multiple user control

                                                                                where XXXXXXXX is the first eight characters of whatever you said in the "DATA BASE NAME IS" statement.

These files are created in the same folder that houses the DBD unless directed otherwise via "File" clauses in the DBD.

During the compile process you are presented with the following choices:

                Create                     -This is a new database. Acquire and initialize the
                                                new data base files.

                Recreate                 -This database exists. Save the data file (.ddd), but
                                                update the control file (.ctl) to this new definition.
                                                Reset and reinitialize the structure files (.ttt and .lll).

                Reformat                -This database exists. Copy and reformat the data
                                                file (.ddd) to reflect additional fields, etc. Update the
                                                control file (.ctl) to reflect the new definition. Reset
                                                and reinitialize the structure files (.ttt and .lll).

                Delete                     -This database exists. Delete all of its files and replace
                                                them with these new versions. Initialize all files.

                Cancel                    -Don't do anything. This was just a test compile.

The display preceding these choices tells you the names and sizes of all of the files that are the result of the compile process.

You can find out more about these choices in the section on Database Maintenance.