It was eventually supplanted by SQL (which is however based on the relational algebra defined by Codd in "Relational Completeness of Data Base Sublanguages"), which IBM developed for its first commercial relational database product.
It was eventually replaced by SQL (which is however based on the relational algebra defined by Codd in "Relational Completeness of Data Base Sublanguages"), which IBM developed for its first commercial relational database product.