Editing SQL (section)

==Distributed SQL processing==
[[DRDA|Distributed Relational Database Architecture]] (DRDA) was designed by a workgroup within IBM from 1988 to 1994. DRDA enables network-connected relational databases to cooperate to fulfill SQL requests.<ref>{{cite journal|last1=Reinsch, R.|title=Distributed database for SAA|journal=IBM Systems Journal|date=1988|volume=27|issue=3|pages=362–389|doi=10.1147/sj.273.0362}}</ref><ref>{{cite book|title=Distributed Relational Database Architecture Reference|date=1990|publisher=IBM Corp. SC26-4651-0}}</ref>

An interactive user or program can issue SQL statements to a local RDB and receive tables of data and status indicators in reply from remote RDBs. SQL statements can also be compiled and stored in remote RDBs as packages and then invoked by package name. This is important for the efficient operation of application programs that issue complex, high-frequency queries. It is especially important when the tables to be accessed are located in remote systems.

The messages, protocols, and structural components of DRDA are defined by the [[Distributed Data Management Architecture]]. Distributed SQL processing ala DRDA is distinctive from contemporary [[distributed SQL]] databases.