Product characteristics
The library maintenance system LMS can be used to create and maintain program libraries and to process the elements contained in them.
Program libraries are BS2000 PAM files that are processed with the program library access method PLAM (and hence also referred to as PLAM libraries).
The main advantages of LMS are as follows:
All element types in a library can be processed by means of uniform statements.
Elements may have identical names and be differentiated by type or version.
Versions are incremented automatically.
The library can be accessed simultaneously by many users and also be written to concurrently.
Different access rights can be assigned for each element.
Access to elements can be monitored.
LMS provides uniform data management and common access functions for most of the data elements involved in the development of software.
Utility routines and compilers can access the data repository and also process individual elements directly.
LMS thus provides vital support in the creation, maintenance, and documentation of programs.
Structure of libraries
A program library is a file with a substructure. It contains elements as well as a directory of the elements stored in it.
An element is a logically related data set, e.g. a file, a procedure, an object module, or a compilation unit. Each element in the library can be addressed independently. Each library has an entry in the system catalog. The user can define the library name and other file attributes such as retention periods and shareability.
The collective storage of several files in a library reduces the load on the system catalog, since only the library is entered there and not each element. It also saves storage space, since library elements are stored in compressed form.
Support for multiple versions
If the delta technique is used for multiple versions of an element, only the differences (deltas) with respect to the previous version are stored. This also helps to save storage space.
When such delta versions are read, LMS inserts the required deltas at the appropriate positions and thus provides the user with a complete element.
LMS supports symbolic version identifiers and automatically increases the version ID in accordance with the selected version format.
Embedding in the program environment
Utility routines of the programming environment such as EDT, compilers, etc., can directly access program libraries.
Documentation
“LMS” user guide [11]