CODASYLstyle

CODASYL style, also known as CODASYL network, is a data model used for representing and organizing data in a database. Developed in the 1960s, it was one of the first data models to be formally defined and widely adopted. The term "CODASYL" is an acronym for the Committee on Data Systems Languages.

In a CODASYL database, data is organized into a network of records, which are interconnected through references. Each record has one or more addresses, which point to other records that are related to it. The network of records is navigated using a set of operators, such as move and read-next, which allow the user to move from one record to the next.

The CODASYL data model has several key features, including:

* Network organization: Records are interconnected and can be navigated using a set of operators.

* Relational structure: Records are related to each other through references and addresses.

* Dynamic record structure: Records can be created, deleted, and modified dynamically.

CODASYL style was widely used in the 1970s and 1980s, particularly in relational databases. However, it has largely been replaced by more modern data models, such as relational and object-relational models. CODASYL style is still used in some legacy databases and systems, but it is no longer a mainstream data model.

Despite its limitations, CODASYL style played an important role in the development of modern database technology. It introduced a new approach to data organization and navigation, which has influenced the design of later data models.