Oracle Rdb
| Company type | Software product |
|---|---|
| Industry | Database management system |
| Predecessor | VAX Rdb/VMS |
| Founded | 1984 |
| Founder | Digital Equipment Corporation (DEC) |
| Fate | Acquired by Oracle Corporation in 1994 |
| Headquarters | United States |
| Products | Oracle Rdb relational database management system |
| Parent | Oracle Corporation |
Oracle Rdb is a relational database management system designed specifically for the OpenVMS operating system. It was first introduced by Digital Equipment Corporation (DEC) in 1984 under the name VAX Rdb/VMS.
Product history
As a component of the VAX Information Architecture, Rdb was engineered to work seamlessly with Digital's suite of database tools and frameworks, including the Application Control Management System, Datatrieve, and the Common Data Dictionary. Its initial interface for queries was a proprietary language called Relational Data Operator (RDO), with later enhancements incorporating support for ANSI SQL.
In 1994, DEC transferred ownership of the Rdb product line to Oracle Corporation, which subsequently rebranded it as Oracle Rdb. Oracle has maintained active development through 2020, with more than fifty percent of the codebase developed after Oracle acquired it. Oracle Rdb remains exclusive to the VMS environment; version 7.0 supports OpenVMS on both VAX and Alpha architectures, version 7.1 targets Alpha exclusively, and versions 7.2 through 7.4 run on Alpha as well as Itanium platforms.
Rdb was among the pioneers in implementing a cost-based optimizer, a feature that later influenced Oracle’s flagship Oracle RDBMS product.
On March 22, 2011, Oracle declared it would cease software development for Itanium processors, designating Oracle Rdb 7.3 as its final significant release for that platform. Nevertheless, following legal action initiated by HP against Oracle, Oracle was obligated to continue porting software updates to Itanium systems for as long as HP marketed those machines.
Despite this commitment, Oracle launched version 7.4.1.0 of Rdb in August 2020 for OpenVMS running on Alpha and Itanium processors. Furthermore, in November 2020, Oracle commenced porting Rdb 7.4 to the x86-64 variant of OpenVMS, demonstrating ongoing dedication to broadening platform availability.
Data access
Users can interact with Oracle Rdb through either SQL (Structured Query Language), RDO (Relational Database Operator), or a combination of both.
Typically, higher-level programming languages access Oracle Rdb by:
- Embedding RDO commands within source code files followed by precompilation (e.g., converting "file.RCO" into "file.COB")
- Embedding SQL statements within source files and precompiling them similarly (e.g., "file.SCO" into "file.COB")
- Keeping SQL commands in separate files compiled with the "SQL Module Language" compiler and then linking them with application code on OpenVMS
For example: $ SQL$MOD file_bas.sqlmod → file_bas.obj $ BASIC file.bas → file.obj $ LINK file.obj,file_bas.obj → file.exe
A variation known as "Dynamic SQL" allows SQL statements to be constructed at runtime using SQLDA (SQL Descriptor Area).
Within the OpenVMS ecosystem, Oracle Rdb is considered a premium upgrade option—albeit an expensive one—for applications originally relying on Record Management Services (RMS) files.
Architecture
Oracle Rdb is constructed atop a foundational database kernel named KODA, which handles essential functions such as locking mechanisms, journaling, and data buffering. This KODA kernel is also utilized by Oracle's CODASYL DBMS (previously VAX DBMS), which follows a network database model.
Rdb on other platforms
VAX Rdb/ELN, Digital’s relational database designed for the VAXELN operating system, shared the Rdb brand but was fundamentally different in architecture from Rdb/VMS. Developed by Jim Starkey, Rdb/ELN was notable as the first commercial database to implement Multiversion concurrency control.
There were ports of Oracle Rdb planned or developed for platforms such as Tru64 and Microsoft Windows NT. Due to insufficient demand, support for Tru64 was discontinued; meanwhile, the Windows NT version never reached release because of the absence of BLISS compiler support. To aid cross-platform compatibility efforts, an abstraction layer called the Common Operating System Interface (COSI) was created.
Additionally, Digital offered ULTRIX/SQL for their Ultrix operating system; however, this product was based on Ingres, not related to Rdb.