DBMS Interview Questions – Set 11

What are the three levels of data abstraction? Following are three levels of data abstraction: Physical level: It is the lowest level of abstraction. It describes how data are stored. Logical level: It is the next higher level of abstraction. It describes what data are stored in the database and what the relationship among those data is. … Read more

DBMS Interview Questions – Set 10

What is System R? How many of its two major subsystems? System R was designed and developed from 1974 to 1979 at IBM San Jose Research Centre. System R is the first implementation of SQL, which is the standard relational data query language, and it was also the first to demonstrate that RDBMS could provide … Read more

DBMS Interview Questions – Set 09

What do you mean by extension and intension? Extension: The Extension is the number of tuples present in a table at any instance. It changes as the tuples are created, updated and destroyed. The actual data in the database change quite frequently. So, the data in the database at a particular moment in time is known … Read more

DBMS Interview Questions – Set 08

What is data abstraction in DBMS? Data abstraction in DBMS is a process of hiding irrelevant details from users. Because database systems are made of complex data structures so, it makes accessible the user interaction with the database. For example: We know that most of the users prefer those systems which have a simple GUI that … Read more

DBMS Interview Questions – Set 07

What is functional Dependency? Functional Dependency is the starting point of normalization. It exists when a relation between two attributes allow you to determine the corresponding attribute’s value uniquely. The functional dependency is also known as database dependency and defines as the relationship which occurs when one attribute in a relation uniquely determines another attribute. … Read more