- Unisys DMSII
The Unisys Data Management System II ("DMSII") is a hierarchical database created by the
Burroughs Corporationin 1972.
As well as having a programmatic interface to high-level languages, it has been associated with the proprietary DMInquiry and ERGO tools.
In recent releases of Unisys Clearpath software it has been renamed as the "Network Database Server".
Originally, DMS II maintained a data dictionary that the application programmer referenced in their source code. The source for the data structures was maintained in an ordinary CANDE source file. That source was then compiled with the DASDL (Data and Structure Definition Language) compiler which created the dictionary (description file) if none existed prior. If a dictionary did exist prior, then the new design indicated by the source file was incorporated into the dictionary and the programs to copy the data from the old file structure(s) and write to the new file structure(s) were automatically generated (a database reorganization task). The application programmer merely needed to re-compile his application source (typically COBOL) against the new description file and the programmer could take advantage of the new data elements in the structures.
DMSII used the concept of "Sets" for data storage. A Data Set contained rows of data and could be random or ordered. Since DMSII supported both hierarchical and relational models, a Data Set could be disjoint or embedded. Table indexes were implemented in Index Sets and could be full sets or subsets of the target Data Set. Subsets could be designated Automatic Subsets and included rules to select records from the target Data Set for inclusion, or Manual Subsets which used programmatic interfaces to insert and remove records. Index Sets included ISAM styles that used field keys to reference records as well as Bit-Vectored sets that used boolean representation of set membership if the Data Set record met conditions defined in the Set.
Wikimedia Foundation. 2010.
Look at other dictionaries:
Attachmate — Corporation Type Private Industry Computer software technology services Founded Bellevue, Washington, 1981 … Wikipedia
DMS — may refer to: Contents 1 Computer Science or IT 2 Science 3 Education … Wikipedia
Grandes sistemas de Burroughs — Los grandes sistemas de Burroughs fueron los más grandes de tres series de computadores mainframes de Burroughs Corporation. Fundada en los años 1880, Burroughs era la más vieja entidad continuamente operando en el área de la computación, pero… … Wikipedia Español
Burroughs large systems — The Burroughs large systems were the largest of three series of Burroughs Corporation mainframe computers. Founded in the 1880s, Burroughs was the oldest continuously operating entity in computing, but by the late 1950s its computing equipment… … Wikipedia
LINC 4GL — LINC is a 4th generation computer language, used mostly on Unisys computer systems.LINC is an abbreviation of Logic and Information Network Compiler.BackgroundLINC was originally developed as a short cut (or template) by two computer application… … Wikipedia