4.     Describe similarities and differences between E-R and "Extended E-R".
            Describe similarities and differences between an OO data model and
            "Extended E-R".
    

    6.      What are the important differences between an Object-Oriented and an
            Object-Relational database?
            Compare when it is more favourable to use relational,
            Object-Oriented, or Object-Relational databases, respectively.
            What is swizzling and what is it used for?
    
    
    7.      In the database area the so-called "three-level architecture",
            which means that a single database can be described using three
            different schemas, is often mentioned.

            a) Explain the meaning of each of the three levels!
            b) Why has this been done?

    6.      Which advantages do you get by using a declarative query language,
            such as SQL?

    8.      Explain (in short) the following terms:
             a) Second normal form
             b) DBA
             c) Sparse index
             d) GRANT
             e) Horizontal fragmentation
             f) Multi-database
             g) Object identifier (OID)
             h) Object-relational database
             i) ODBC

    6.      What is ODBC?
            Why is ODBC needed?
            Describe the architecture of ODBC. Draw a picture.
            What is the difference between JDBC and ODBC?
    
    7.      What is "referential integrity" in modern relational databases?
            What are "domain constraints"?
            How is authorization specified in modern relational databases?
            How are views used for authorization?
    
    

    4.      The Swedish Film Institute has to choose between storing the
            statistics in a database, which is managed by a database
            management system, or storing the data in ordinary files,
            which are handled by a program written in some conventional
            programming language (such as C++ or Java).
            Which advantages and disadvantages are there with the database alternative?
    
    6.      How are security privileges managed in SQL?
            What security privileges are supported by SQL?
            Give example of a scenario for their use.
            How does one handle that different users can access different
            parts of a relation? Give examples.


    7.      What are the three most important join algorithms?
            Outline their functioning through pseudo code.

7.      Show how cost based optimization is used for
        translating the following query into an optimal execution plan: 
          SELECT D.DNAMN FROM EMPLOYEE E, DEPT D WHERE
                 E.DNO = E.DNO AND E.NAME = "Tore"
        Show how the cost based query optimization transforms the relational
        algebra expression into an optimal expression where also the
        join method is indicated. (Nested Loop or Sort Merge Join).
        There are 100000 employees and 300 departments.
        There are sorted indexes (B-trees) on E.SSN(primary), E.DNO, 
        D.DNO(primary).