A history of Databases

By arocruz8

  • 1951

    The computer UNIVAC 1 was created

  • IBM’s computer´s

    The UNIVAC was followed by IBM’s 701 in 1953 and 650 in 1954. Data could now be processed much faster and with fewer errors compared with manual systems.

  • Sequential Systems 1950´s

    Are individual files were composed of records organised in some predetermined order. Although not a database because there was no one integrated data source

  • Random Access

    IBM introduced hard disk drives which allowed direct access to data, these were relatively low capacity and expensive compared to tape system.

  • Origins of Modern Databases

    COBOL and CODASYL languages were developed

  • Hierarchical Databases 1968 - 1970´s

    Hierarchical databases are no longer common, the structure of a hierarchical database relies on pointers.

  • PL/1 and IMS

    IBM created PL/1 programming language and a database know as IMS for the IBM´s series 360

  • Transaction Processing and ACID

    ACID (Atomicity, Consistency, Isolation, Durability) is a set of properties of database transactions intended to guarantee validity even in the event of errors, power failures, etc. In the context of databases, a sequence of database operations that satisfies the ACID properties is called a transaction.

  • Two-Phase Commit

    1. The request phase a coordinating process sends a query to commit message to all other processes.
    2. In the commit phase the coordinator sends a message to the other processes which attempt to complete the commit. If any one process fails, all processes will execute a rollback

  • Relational Databases 1970´s

    The basis of a relational system is a series of tables of records each with specific attributes linked by a series of joins. These joins are created using foreign keys which are attribute(s) containing the same data as another tables primary key. A primary key is a unique identifier of a record in a table.

  • Network Databases 1980-1990´s

    It´s a type of database model where multiple member records or files can be linked to multiple owner files and vice versa.

  • Object Oriented Databases

    The data/information is represented in the form of objects. Object oriented structures such as hierarchies, aggregation and pointers are being introduced.

  • SQL (Structured Query Language)

    SQL is a language used in programming and designed for managing data . Was the first commercial language for relational model.

  • Data Warehouse

    The concept behind a data warehouse is that it can store data generated by different systems in the organisation, not just transactions form the database. It´s a central repository of data in an organisation storing historical data and being constantly added to by current transactions