March 2022
Intermediate to advanced
682 pages
22h 58m
English
The relational model was designed to represent data that consists of single-valued attributes of a small collection of data types, related in relatively simple ways and typically used in traditional data processing. As discussed in Section 9.1, the original relational model lacks features needed to represent the more complex types and relationships necessary for advanced applications. The industry responded to this challenge by proposing the object data model as a new data model. Vendors of relational DBMSs, including Oracle, IBM, Sybase, Informix, PostgreSQL, and Microsoft, met this competition by extending their relational products to incorporate features of the object data model. The SQL:1999 standard also ...