Friday, August 24, 2007

10 Basic Interview Questions for Oracle

For Basic SQL:

  1. How do you convert a date to a string? To_char. A bonus would be that they always include a format mask.

  2. What is an aggregate function? Grouping, sums or counts, etc.

  3. What is an interval? Specifies a period of time.

  4. What is a nested subquery? A subquery in a where clause.

  5. What is the dual table? A single row table provided by oracle for selecting values and expressions.

For Basic PL/SQL:

  1. Describe the block structure of PLSQL. Declaration, Begin, exception, end.

  2. What is an anonymous block? Unnamed PL/SQL block.

  3. What is a PL/SQL collection? PL/SQL Table, Varray, PL/SQL Array, etc.

  4. What is the difference between an explicit cursor and a select into? An explicit cursor is declared in the declaration section, a select into is declared in the body of the code.

  5. Why would you choose to use a package versus straight procedures and functions? I look for maintenance, grouping logical functionality, dependency management, etc. I want to believe that they believe using packages is a "good thing".

Is this list helpful to you? Would you like me to do a series on interviewing and interview questions?