TAILIEUCHUNG - Lecture Database System: Chapter 2 - The Relational Data Model & SQL

Chapter 2 - The Relational Data Model & SQL includes about Relational Model Concepts, Relational Model Constraints and Relational Database Schemas, Update Operations and Dealing with Constraint Violations, Basic SQL. | CSC271 Database Systems Lecture # 2 Components of the DBMS Environment Components of DBMS Environment Hardware Can range from a PC to a network of computers. Software DBMS, operating system, network software (if necessary) and also the application programs. Data Used by the organization and a description of this data called the schema. Components of DBMS Environment Procedures Instructions and rules that should be applied to the design and use of the database and DBMS. People Discussed in the next section Roles in the DB Environment Data Administrator (DA) Database planning Development and maintenance of standards, policies and procedures Database Designers (Logical/Physical) Logical and Physical database design Application Programmers Develop Applications Roles in the DB Environment Database Administrator (DBA) Physical realization of the database Physical database design and implementation Security and integrity control Maintenance of the operational system Ensuring satisfactory performance of the applications for users End Users Naive Sophisticated History of Database Systems Roots of the DBMS Apollo moon-landing project, 1960s NAA (North American Aviation), prime contractor for the project Developed a software GUAM (Generalized Update Access Method), hierarchical In mid–1960s IBM joined NAA, result was IMS (Information Management System) History of Database Systems IDS (Integrated Data Store) By General Electric, network, mid-1960 CODASYL Conference on Data Systems Languages DBTG Data Base Task Group History of Database Systems DBTG proposal (1971) included following components for DB system architecture: The schema The subschema A data management language Schema DDL Subschema DDL DML Proposal was not formally adopted by ANSI History of Database Systems E. F. Codd, 1970 IBM Research Laboratory Relational model System R project by IBM’S San Jose Research Laboratory California Result of this project Development of SQL Commercial relational DBMS .

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