Oracle DBA Interview Questions and Answers for Experienced - 3

Question: 11

How many columns can be used to create a composite index?

A composite index can support 32 columns as long as total size of the columns does not exceed DB_BLOCK_SIZE.

Question: 12

What command would you use to encrypt a PL/SQL application?

The WRAP command can be used to encrypt a PL/SQL application.

Question: 13

How would you determine the time zone under which a database was operating?

You can determine the time zone under which a database was operating by using the select DBTIMEZONE from dual; statement.

Question: 14

What does coalescing a tablespace do?

Coalescing is used to combine fragmented space into larger extents.

It is valid for dictionary managed tablespace and defragments space by coming neighboring free extends into larger single extents.

Question: 15

Can you disable and enable primary key?

Yes, you can use the following statements to enable and disable primary key constraints

Alter table <table_name> enable constraint <constraint_name>;

Alter table <table_name> disable constraint <constraint_name>;

Related Questions