Oracle Certification Exam Interview Preparation Guide
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Oracle Certification guideline for job interview preparation. Explore list of Oracle Certification frequently asked questions(FAQs) asked in number of Oracle Certification interviews. Post your comments as your suggestions, questions and answers on any Oracle Certification Interview Question or answer. Ask Oracle Certification Question, your question will be answered by our fellow friends.

25 Oracle Certification Questions and Answers:

1 :: How to create a multiple databases with the same configuration?

Applications can create multiple databases with in a single file.This is useful when database are both numerous and reasonably small in order to avoid creating a large number of underlying files.Putting multiple databases in a single physical file is an administrative convenience and unlikely to affectdatabase performance.

3 :: what is the difference between TRUNCATE, DELETE, DROP?

1) Drop will drop the records from the table along with its structure.All the indexes associated with it will also deleted and there is no rollback.
2) Delete will deletes the records of the table but the structure of the table is retained back.It is a DML operation which is slower but provides rollback facility.
3) Truncate is a DDL command which is faster ,retain structure of the table and rollback is possible.It allocates memory usually after truncating so structure is retained.

5 :: What is the difference between primary key and foreign key

Primary Key is unique Key entire the table and which is
also NOT NULL
where as foriegn key is the null & which references the
primary key .

6 :: How to use STANDBY_ARCHIVE_DEST parameter and explain its need?

STANDBY_ARCHIVE_DEST is relevant only for a standby database in managed recovery mode. It specifies the location of archive logs arriving from a primary database.

7 :: Explain What is the use of PARALLEL_ADAPTIVE_MULTI_USER initialization parameter?

When we set to PARALLEL_ADAPTIVE_MULTI_USER true enables an adaptive algorithm designed to improve performance in multiuser environments that use parallel execution. The algorithm automatically reduces the request degree of parallelism based on the degree at the system load at query startup time.

10 :: What is row chaining and row migration?

We will migrate a row when an update to that row would cause it to not fit on the block anymore (with all of the other data that exists there currently). A migration means that the entire row will move and we just leave behind the. So, the original block just has the rowid of the new block and the entire row is moved.
Row chaining nstead of just having a forwarding address on one block and the data on another we have data on two or more blocks.