Things to know before your Oracle DBA job interview in Dallas

With the competition for Oracle DBA jobs in US getting bigger than ever before, it has become vital to prepare for your job interview thoroughly.  Apart from knowing how to sell yourself at the interview and preparing a lively application letter and resume, you should also be prepared to answer some of the common interview questions. Here is a look at popular Oracle DBA questions along with answers.

What is Oracle?

Oracle refers both to the company and the database server used for managing data in a structured and efficient manner. Oracle allows many users to simultaneously access the same data and facilitates storage and retrieval in a multiuser environment. It also blocks unauthorized access and offers effective options for failure recovery.

Can you define an Oracle Database?

Oracle offers you the means to create and manage the Oracle database. The database stores system, user, and control info via its physical and logical provisions. Oracle database server is the software that manages the database. The Oracle database system as a whole is responsible for running oracle and its physical database.

What are the responsibilities of a DBA?

DBA is responsible for creating and removing users and also managing the privileges given to each of the user. The DBA is in charge of administering users and security, evaluation database performance, managing schema objects, automation, scheduling, backup, recovery of data, among others.

Can you name some of the Oracle database objects?

The standard database objects in Oracle include tables, sequences, tablespaces, views, indexes, and synonyms.

Define an Oracle index

An index is created on columns of a table to have direct access to rows. This optional arrangement helps in improving the efficiency of data retrieval.

Explain RAW datatype

RAW is employed for storing values in binary. In a table, RAW’s maximum limit is 32767 bytes.

Explain BLOB

BLOB is a data type – a binary string of variable length used for storing 2GB.

What is NULL value?

NULL value stands for missing or unidentified data. It is a place holder or default entry that denotes the absence of actual data.

Explain WITH CHECK OPTION

It is an item that states the level of check to be carried out in DML statements. It is used for avoiding changes to a view that would lead to results not enclosed in the sub query.

How is varchar different from varchar2?

While Varchar can store up to 2000 bytes, varchar2 can store double the memory i.e. 4000 bytes. Varchar and varchar2 are differentiated by space – Varchar occupies space for NULL value, whereas Varchar2 doesn’t occupy any space.

Why do you need the NVL function?

NVL function is required for swapping NULL values with any other value.

How to extract field detail of a table?

One can use Describe <Table_Name> to get the field detail of a particular table.

Those are some of the common questions employers ask at Oracle DBA job interviews.

In case you are looking for Oracle DB jobs in the US or Dallas TX in particular, here is an updated list of latest vacancies.