DATABASE | ORACLE | ORACLE INTERVIEW QUESTION AND ANSWERS 3 | WHAT IS NULL VALUE? | DEFINE TRANSACTION? | WHAT IS THE DIFFERENCE BETWEEN SQL&ORACLE? | WHAT ARE DIFFERENT ORACLE DATABASE OBJECTS? | WHAT IS HASH CLUSTER?

Oracle Interview Question and Answers:

11.     what is null value?
      Null Value is neither zero nor it is a blank space. It is some unknown value which occupies 4 bytes of space of memory in SQL.

12.     Define transaction?
      A transaction is a sequence of SQL statements that Oracle Database treats as a single unit.

13.     what is the difference between sql&oracle?
      SQL is Stuctured Query Language.Oracle is a Database.SQL is used to write queries against Oracle DB.

14.     What are different Oracle database objects?
      TABLES
    VIEWS
    INDEXES
    SYNONYMS
    SEQUENCES
    TABLESPACES

15.     What is hash cluster?
      A row is stored in a hash cluster based on the result of applying a hash function to the row's cluster key value. All rows with the same hash key value are stores together on disk.