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What is a Database? SECTION 1

What is a Database? SECTION 1. Database Technology and its Evolution. Decades long evolution Early data processing systems Today's systems New technology. File-Oriented Systems. Early business computer systems Data processing systems Sequential processing Application program.

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What is a Database? SECTION 1

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  1. What is a Database?SECTION 1

  2. Database Technology and its Evolution • Decades long evolution • Early data processing systems • Today's systems • New technology

  3. File-Oriented Systems • Early business computer systems • Data processing systems • Sequential processing • Application program

  4. Data from a File-Oriented System

  5. Random Access Processing • Limitations of sequential processing systems • Sequential processing leads to additional work • Solved by :

  6. Limitations of Traditional File Systems • Data redundancy • Poor data control • Inadequate data manipulation capabilities • Excessive programming effort

  7. Information as a Resource • What is an Information System (IS)? • A Management Information System (MIS) • Data • Information

  8. A database • A database system • Database Management System

  9. Database Systems • Data models • Hierarchical model • Pointer

  10. Files with a Hierarchical Relationship

  11. CUSTOMER INVOICE INVOICE LINE

  12. CUSTOMER INVOICE STORE INVOICE LINE CONTACT

  13. SALES REP CUSTOMER INVOICE STORE INVOICE LINE CONTACT • A network model

  14. Relational Databases Systems • Pointers - strengths and weaknesses • E.F. Codd (1970)

  15. CUSTOMER No physical connection INVOICE MANUFACTURER INVOICE LINE PRODUCT • For each customer, identify the manufacturer of the ordered products. An Illustration of Problems with Pointers

  16. Tables • Manipulation languages Codd’s proposal

  17. Database Systems: Hardware, Software, Data, and People • A complete database systems consists of: • Hardware • Software • DBMS • Application software

  18. Data dictionary • Data security and integrity DBMS

  19. Database User View 3 User View 2 User View 1 Data Item

  20. Data • People

  21. Database & Instance Typical components of a server Disk Memory (RAM) CPU

  22. Database: The actual database is a collection of tables or files that reside on the disk Memory (RAM) Disk Database Table 4 Table 1 Table 2 Table 5 Table 3 Table n CPU Two main types of database files: Data Metadata

  23. Instance: Software running in memory Memory (RAM) Disk DBMS Instance Database Table 4 Table 1 Table 2 Table 5 Table 3 Table n CPU

  24. An Instance: Multiple databases Memory (RAM) Disk DBMS DB02 DB01 Instance Table 4 Table 4 Table 1 Table 1 Table 2 Table 2 Table 5 Table 5 Table 3 Table 3 Table n Table n CPU

  25. Multiple Instances: Single database Instance 01 Instance 02 Memory (RAM) Disk DBMS Database Table 4 Table 1 Table 2 Table 5 Table 3 Table n CPU

  26. Multiple Instances: Single database Instance 02 Instance 01 Memory (RAM) DBMS Disk Database CPU01 Table 4 Table 1 Table 2 Table 5 Table 3 Table n Memory (RAM) DBMS CPU02

  27. INSTANCE OASIS Multiple databases

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