21 interview questions on Oracle Database for developers (2026)

Easy

3 votes195 runs0 comment

What type of join returns all rows in the left-hand table, even if they have no match in the right-hand table?

Tech support officier

Koala rareat Feb 11, 2025

Easy

2 votes183 runs0 comment

How to rename a column in an existing table in Oracle?

Tech support officier

Koala rareat Feb 11, 2025

Easy

1 vote174 runs0 comment

What is the result of this Oracle query?

Tech support officier

NVL

Koala rareat Feb 11, 2025

Hard

1 vote167 runs0 comment

Which Oracle tool can be used to analyze SQL query performance?

Tech support officier

sql

Koala rareat Feb 11, 2025

Expert

1 vote162 runs0 comment

What does the following SQL query return?

Tech support officier

database

sql

Koala rareat Feb 11, 2025

Hard

1 vote161 runs0 comment

Where does Oracle log system errors and critical events ?

Tech support officier

logging

troubleshooting

Koala rareat Feb 11, 2025

Hard

1 vote155 runs0 comment

What type of index is recommended for columns with few distinct values in Oracle?

Tech support officier

indexes

bitmap

Koala rareat Feb 11, 2025

Medium

0 vote173 runs0 comment

What happens after executing this code in Oracle?

Tech support officier

transactions

rollback

Koala rareat Feb 11, 2025

Easy

0 vote167 runs0 comment

What is the main function of the `DBMS_SCHEDULER` package in Oracle?

Tech support officier

database

scheduling

Koala rareat Feb 11, 2025

Easy

0 vote156 runs0 comment

What does this PL/SQL code do?

Tech support officier

cursors

loops

Koala rareat Feb 11, 2025

Medium

0 vote154 runs0 comment

What are the primary uses of a Materialized View in Oracle?

Tech support officier

Koala rareat Feb 11, 2025

Medium

0 vote151 runs0 comment

What does the "INSERT /+ APPEND /" instruction do in Oracle?

Tech support officier

sql

insert

direct path

Koala rareat Feb 11, 2025

Medium

0 vote149 runs0 comment

What is the role of the SYSTEM tablespace in Oracle?

Tech support officier

database

tablespace

Koala rareat Feb 11, 2025

Easy

0 vote146 runs0 comment

How to grant SELECT rights on a table in Oracle?

Tech support officier

Koala rareat Feb 11, 2025

Hard

0 vote145 runs0 comment

What is the length of the string "\u00e9" in Oracle?

Tech support officier

Koala rareat Feb 12, 2025

Medium

0 vote144 runs0 comment

Which Oracle architecture component contains the in-memory data cache?

Tech support officier

SGA

Koala rareat Feb 11, 2025

Medium

0 vote144 runs0 comment

How to backup a database with RMAN in Oracle?

Tech support officier

backup

RMAN

Koala rareat Feb 11, 2025

Easy

0 vote143 runs0 comment

What's the difference between VARCHAR2 and CHAR in Oracle?

Tech support officier

varchar2

char

Koala rareat Feb 11, 2025

Easy

0 vote128 runs0 comment

What happens after executing this code in Oracle?

Tech support officier

transactions

rollback

Koala rareat Feb 11, 2025

Medium

0 vote117 runs0 comment

How to remove all data from an Oracle table without logging the transaction history?

Tech support officier

sql

truncate

Koala rareat Apr 22, 2025

21 interview questions on Oracle Databasefor developers (2026)

Test your technical skills before an interview of Oracle Database with 21 corrected questions. Beginner, Intermediate or Expert level.

What type of join returns all rows in the left-hand table, even if they have no match in the right-hand table?

How to rename a column in an existing table in Oracle?

What is the result of this Oracle query?

Which Oracle tool can be used to analyze SQL query performance?

What does the following SQL query return?

Where does Oracle log system errors and critical events ?

What type of index is recommended for columns with few distinct values in Oracle?

What happens after executing this code in Oracle?

What is the main function of the `DBMS_SCHEDULER` package in Oracle?

What does this PL/SQL code do?

What are the primary uses of a Materialized View in Oracle?

What does the "INSERT /+ APPEND /" instruction do in Oracle?

What is the role of the SYSTEM tablespace in Oracle?

How to grant SELECT rights on a table in Oracle?

What is the length of the string "\u00e9" in Oracle?

Which Oracle architecture component contains the in-memory data cache?

How to backup a database with RMAN in Oracle?

What's the difference between VARCHAR2 and CHAR in Oracle?

What happens after executing this code in Oracle?

How to remove all data from an Oracle table without logging the transaction history?

21 interview questions on Oracle Databasefor developers (2026)

Test your technical skills before an interview of Oracle Database with 21 corrected questions. Beginner, Intermediate or Expert level.

What type of join returns all rows in the left-hand table, even if they have no match in the right-hand table?

How to rename a column in an existing table in Oracle?

What is the result of this Oracle query?

Which Oracle tool can be used to analyze SQL query performance?

What does the following SQL query return?

Where does Oracle log system errors and critical events ?

What type of index is recommended for columns with few distinct values in Oracle?

What happens after executing this code in Oracle?

What is the main function of the `DBMS_SCHEDULER` package in Oracle?

What does this PL/SQL code do?

What are the primary uses of a Materialized View in Oracle?

What does the "INSERT /*+ APPEND */" instruction do in Oracle?

What is the role of the SYSTEM tablespace in Oracle?

How to grant SELECT rights on a table in Oracle?

What is the length of the string "\u00e9" in Oracle?

Which Oracle architecture component contains the in-memory data cache?

How to backup a database with RMAN in Oracle?

What's the difference between VARCHAR2 and CHAR in Oracle?

What happens after executing this code in Oracle?

How to remove all data from an Oracle table without logging the transaction history?

What does the "INSERT /+ APPEND /" instruction do in Oracle?