ORACLE Interview Questions and Answers
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(Continued from previous part...)
GENERAL INTERVIEW QUESTIONS (2)
16.What is the advantage of a stored procedure over a database trigger ?
We have control over the firing of a stored procedure but we have no control over the firing of a trigger.
17.What is the maximum no. of statements that can be specified in a trigger statement ?
One.
18.Can views be specified in a trigger statement ?
No
19.What are the values of :new and :old in Insert/Delete/Update Triggers ?
INSERT : new = new value, old = NULL
DELETE : new = NULL, old = old value
UPDATE : new = new value, old = old value
20.What are cascading triggers? What is the maximum no of cascading triggers at a time?
When a statement in a trigger body causes another trigger to be fired, the triggers are said to be cascading. Max = 32.
21.What are mutating triggers ?
A trigger giving a SELECT on the table on which the trigger is written.
22.What are constraining triggers ?
A trigger giving an Insert/Updat e on a table having referential integrity constraint on the triggering table.
23.Describe Oracle database's physical and logical structure ?
Physical : Data files, Redo Log files, Control file.
Logical : Tables, Views, Tablespaces, etc.
24.Can you increase the size of a tablespace ? How ?
Yes, by adding datafiles to it.
26.What is the use of Control files ?
Contains pointers to locations of various data files, redo log files, etc.
27.What is the use of Data Dictionary ?
Used by Oracle to store information about various physical and logical Oracle structures e.g. Tables, Tablespaces, datafiles, etc
28.What are the advantages of clusters ?
Access time reduced for joins.
29.What are the disadvantages of clusters ?
The time for Insert increases.
30.Can Long/Long RAW be clustered ?
No.
(Continued on next part...)
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