Set - 3

Question 66 :

What are the common Import/ Export problems? (for DBA )

Answer :

ORA-00001: Unique constraint (...) violated - You are importing duplicate rows. Use IGNORE=NO to skip tables that already exist (imp will give an error if the object is re-created).
ORA-01555: Snapshot too old - Ask your users to STOP working while you are exporting or use parameter CONSISTENT=NO
ORA-01562: Failed to extend rollback segment - Create bigger rollback segments or set parameter COMMIT=Y while importing
IMP-00015: Statement failed ... object already exists... - Use the IGNORE=Y import parameter to ignore these errors, but be careful as you might end up with duplicate rows.

Question 67 :

Why is it preferable to create a fewer no. of queries in the data model?

Answer :

Because for each query, report has to open a separate cursor and has to rebind, execute and fetch data.

Question 68 :

Where is the external query executed at the client or the server?

Answer :

At the server.

Question 69 :

Where is a procedure return in an external pl/sql library executed at the client or at the server?

Answer :

At the client.

Question 70 :

What is coordination Event?

Answer :

Any event that makes a different record in the master block the current record is a coordination causing event.