The user must initialise the ZEBRA memory management system before calling any of the HEPDB routines. This may either be done explicitly, e.g. via a call to HLIMIT. Alternatively, the routine CDSTART may be used.
Then, for each data base file, a call to CDOPEN initializes the HEPDB/RZ control for the corresponding file. When using several data base files, the user should be careful always to give the complete pathnames for all subsequent references to the directories.
For an optimum usage of the RZ system, the user is advised to have a reasonably large allocation for the system division. This is performed automatically if the option CDOPEN.
A unique numeric identifier is associated to every given top directory (every file). The HEPDB package defines by default an identifier increasing monotonically as the user makes the successive calls to CDOPEN. The choice of the identifier can however be imposed by the user, by presetting IQUEST(1), a Zebra short term communication variable, to the desired value, before calling CDOPEN. The numeric identifier assigned to each directory packed with that of the top directory, is stored in the corresponding NODE bank. This permits to record in a simple way which data objects have been used in a given program execution.
The DICTIONARY directory, initially generated under control of CDNEW, is dumped into memory at every call to CDOPEN. It can be expanded at user's request to store mnemonics (up to 8 characters) for the elements of the data objects. These are mainly used in HEPDB interactive applications. For each directory, the mnemonics are stored in a data object of the DICTIONARY directory, with key 1 set equal to the numeric identifier of the corresponding directory. The routine which can be used for entering or retrieving the information is CDNAME. The aliases, in the DICTIONARY directory, can be stored and retrieved through the routine CDALIA.
The HELP directory, also generated automatically under control of CDNEW, at the time of creating the data base, is initially empty. The user should enter the help information as an ASCII file through the routine CDHELP. The content of the file is encoded as a computer independent single data object with the key 1 set equal to the numeric identifier of the relevant directory. The help information can be subsequently retrieved, decoded and displayed, also through the routine CDHELP.