ISBL

ISBL (Information Systems Base Language) is the relational algebra notation that was invented for PRTV, one of the earliest database management systems to implement E.F. Codd's relational model of data.

There are six main operations in ISBL that derive their names from relational algebra but are more generalized in action than their namesakes. These are selection, projection, union, intersection, difference and join.: 288 

Example

OS = ORDERS * SUPPLIERS
LIST OS: NAME="Brooks" % SNAME, ITEM, PRICE

See also

References

  1. ↑ Todd, S. J. P. (1976). "The Peterlee Relational Test Vehicle—a system overview". IBM Systems Journal. 15 (4): 285–308. doi:10.1147/sj.154.0285. ISSN 0018-8670.