DBMS Interview Questions

Database Management System

• A Database Management System is a type of software.

SQL Queries

• The query SELECT * FROM instructor ORDER BY salary ____, name ____ can be replaced with SELECT name FROM instructor1 WHERE salary BETWEEN 90000 AND 100000.
• The query SELECT name, course_id FROM instructor, teaches WHERE instructor_ID= teaches_ID is used to query information from the database and insert tuples into, delete tuples from, and modify tuples in the database.

Data Storage

• The term "FAT" stands for File Allocation Table.
• The maximum size that is supported by FAT is 4GB.
• The term "NTFS" refers to New Technology File System.
• The maximum size that is supported by NTFS is 256TB.

Data Warehouse

• A huge collection of information or data accumulated from several different sources is known as a data warehouse.
• A data warehouse can be used to extract or filter the data and information from the data.

Data Redundancy

• Redundancy refers to the copies of the same data occupying the memory space at multiple places.

Data Abstraction

• Metadata refers to the data about data.
• The physical level of data abstraction describes exactly how the data is actually stored.

Database Administration

• The term "DBA" refers to Database Administrator.

File System

• A file is a collection of all related data.
• The term "Data" refers to the facts and statistics collected together for reference or analysis.

Relational Database

• Rows of a relation are known as tuples.
• The number of tuples in a relation is called the cardinality of the relation.
• An attribute is a column or field in a relational database.
• The number of attributes in a relation is called the degree of the relation.

SQL Commands

• The INSERT command is a type of Data Manipulation Command.
• The CREATE command is a type of Data Definition Language command.
• The DELETE command is used to delete the existing row in a table.
• The COMMIT command is used to save any transaction permanently into the database.

Data Modeling

• Top-down approach is a method in which the entity's higher level can be divided into two lower sub-entities.
• Bottom-up approach is a method in which the multiple lower entities are grouped together to form a single higher-level entity.