RDB

from The Free On-line Dictionary of Computing (8 July 2008)

Oracle Rdb
Rdb

   <database> A set of {relational database} products originally
   known as Rdb from {Digital Equipment Corporation}, but
   purchased by {Oracle Corporation} in 1994.  The current (October
   1996) versions are Oracle Rdb V7.0 for {OpenVMS} {VAX}, Oracle
   Rdb V7.0 for OpenVMS {Alpha}, and Oracle Rdb V7.0 for {Digital
   UNIX}.

   This release of Oracle Rdb includes advances in {non-stop
   computing} for {business critical} applications, improvements
   to {OLTP} performance, and easy {client/server} application
   development.  It also includes an {ODBC} Driver.

   (1996-10-30)

from The Free On-line Dictionary of Computing (8 July 2008)

rdb

   A roll-your-own {database}, created in the {Unix} toolkit
   philosophy.  It appears to be written in the {awk} language,
   and is very compatible with awk.  It uses awk's syntax and can
   be combined with awk commands.

   The definitive introduction is "Unix Relational Database
   Management: Application Development in the Unix Environment",
   by Rod Manis, Evan Schaeffer, and Robert Jorgensen, published
   by Prentice Hall.  The book tells how to use rdb to create
   database/spreadsheets in the awk tradition, only easier. It's
   a good way to get into programming for novices.  It's also a
   good way to learn DB theory and construction quite painlessly.

from V.E.R.A. -- Virtual Entity of Relevant Acronyms (June 2006)

RDB
       Receive Data Buffer

from V.E.R.A. -- Virtual Entity of Relevant Acronyms (June 2006)

RDB
       Rigid Disk Block (Amiga, Commodore)

from V.E.R.A. -- Virtual Entity of Relevant Acronyms (June 2006)

RDB
       Relational DataBase (DB)