DEC-DSM-ForOpenVMS

This document describes Digital Standard MUMPS (DSM) for OpenVMS VAX and AXP, emphasizing its reliability and performance for mission-critical computing.

Key aspects of DSM include:

• Integrated Environment: It's a complete package with a high-level interpretive programming language, a multi-user data management system, and the DSM Application Software Library (DASL). DASL includes a 4GL application generator, data dictionary, and SQL-compliant query driver, automating many development tasks.
• Cross-Platform Compatibility: DSM is identical and fully compatible across both VAX and Alpha AXP platforms, ensuring applications developed on one run seamlessly on the other, protecting computing investments.
• Reliability & Data Integrity: Designed for high-availability production systems, DSM offers robust features like before- and after-image journaling for transaction recording, rapid recovery from CPU failures, and full support for VMScluster automatic failover. It adheres to ACID properties (Atomicity, Consistency, Isolation, Durability) for transaction processing, ensuring database integrity.
• Performance & Productivity: Optimized for transaction processing with a fast interpreter, precompiler, and efficient memory management. It includes a powerful symbolic debugger and error-handling capabilities, designed to enhance programmer productivity.
• Interoperability & Scalability: DSM provides extensive interoperability through a callable routines library (allowing non-M languages to access DSM data) and an external call interface (allowing DSM to call other language functions). It supports database sharing via VMScluster environments and DSM Distributed Data Processing (DDP) networking protocols (DECnet, Ethernet, TCP/IP), facilitating growth and multi-system access.
• GUI Development: It offers a complete X Window System interface (DECwindows Motif) with support for X Image Extensions (XIE) and DECimage Application Services, enabling the creation of graphical user interfaces.
• OpenVMS Advantage: DSM is layered on the rich OpenVMS operating system, leveraging DCL, editors, and allowing integration with other OpenVMS layered software products like word processors and spreadsheets.

DSM is a popular choice for developing mission-critical applications in industries such as finance, manufacturing, and healthcare, particularly for transaction-intensive and shared, database-intensive systems.