The ZEBRA RZ [bib-ZEBRARZ] package uses random access files, which can reside on direct access devices or in memory. RZ files are organised in a hierarchical manner, much like the Unix file system. Thus, data is accessed or stored using a Unix-like pathname, plus one or more identifiers known as keys.
The ZEBRA RZ package was designed for use in High Energy Physics experiments, and thus is well suited to applications such as HEPDB.
In HEPDB, data is stored in one or more ZEBRA RZ files. Typically, one might use separate subdirectories for the different detector components. Again, for any given subdetector, separate subdirectories could be used for the various types of information that are to be stored for that component. Thus, one might have subdirectories such as TEMPERATURE, GAS, ALIGN and so on. For efficiency reasons, it is also recommended to store information with widely differing update frequencies in different directories. Thus, one might have a subdirectory per subdetector for constant or pseudo-constant information, such as the number of wires in a cell, and other directories, as shown above, for information which varies more rapidly, such as gas pressures.