Database management systems raghu ramakrishnan

What are the 4 types of DBMS?
Edgar Frank "Ted" Codd (19 August 1923 – 18 April 2003) was an English computer scientist who, while working for IBM, invented the relational model for database management, the theoretical basis for relational databases and relational database management systems..
What is database management system theory?
DB2: The relational database.
IBM\xae DB2\xae for z/OS\xae (often referred to as "DB2") is IBM's relational database management system (DBMS) for the z/OS operating system.
DB2 is designed for and tightly integrated with the IBM System z\xae mainframe to leverage the strengths of System z..
Who designed database management system?
Data management is the practice of collecting, organising, and accessing data to support productivity, efficiency, and decision-making..
Who was the first creator of DBMS?
The first DBMS was developed in the early 1960s when Charles Bachman created a navigational DBMS known as the Integrated Data Store.
Shortly after, IBM developed Information Management System (IMS), a hierarchical DBMS designed for IBM mainframes that's still used by many large organizations today..

What are the 4 types of DBMS?