A relational data base system,FODAS, is designed and implemented using the concept of multi-scheme architecture.
The data language of FODAS, FDL, is constructed on the basis of SQL and has three facilities: query facility, data definition facility, and data manipulation facility.
In order to process the given FDL statement, it should be parsed by LALR(1) parser and directly interpreted by means of syntax_directed translation.
Data definition and data manipulation facility are rather directly interpreted, while query facility is processed by interpreting the query tree constructed during the syntax_directed translation.
Especially, multi_relation query associated with more than one relations is executed by decomposing it into a sequence of one relation queries and processing those one relation queries separately.