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Oracle Sample Questions : Oracle Interview Questions

81. What is Auditing ?

    Answer: The database has the ability to audit all actions that take place within it. a) Login attempts, b) Object Accesss, c) Database Action Result of Greatest(1,NULL) or Least(1,NULL) NULL

82. While designing in client/server what are the 2 imp.things to be considered ?

    Answer: Network Overhead (traffic), Speed and Load of client server

83. What are the disadvantages of SQL ?

    Answer: Disadvantages of SQL are :

    • Cannot drop a field
    • Cannot rename a field
    • Cannot manage memory
    • Procedural Language option not provided
    • Index on view or index on index not provided
    • View updation problem

84. When to create indexes ?

    Answer: To be created when table is queried for less than 2% or 4% to 25% of the table rows.

85. How can you avoid indexes ?

    Answer: To make index access path unavailable

    • Use FULL hint to optimizer for full table scan
    • Use INDEX or AND-EQUAL hint to optimizer to use one index or set to indexes instead of another.
    • Use an expression in the Where Clause of the SQL.

86. What is the result of the following SQL :
    Select 1 from dual UNION Select 'A' from dual;

    Answer: Error

87. Can database trigger written on synonym of a table and if it can be then what would be the effect if original table is accessed.

    Answer: Yes, database trigger would fire.

88. Can you alter synonym of view or view ?

    Answer: No

89. Can you create index on view

    Answer: No.

90. What is the difference between a view and a synonym ?

    Answer: Synonym is just a second name of table used for multiple link of database.View can be created with many tables, and with virtual columns and with conditions.But synonym can be on view.