Quiz 1 - Introduction to Database Systems

Which of the following can not be said as a solution that database systems offer?

• Security problems

• Concurrent access by multiple users

• Alternatif for Java

• Data isolation

Which one is NOT a Data Model type?

• Relational model

• Excel Model

• Entity-Relationship data model

• Semi-structured data model (XML, JSON)

Which one can NOT be said for SQL Query Language

• SQL query language is nonprocedural.

• A query takes as input several tables (possibly only one) and always returns a single table.

• SQL is NOT a Turing machine equivalent language

• SQL supports actions such as input from users, output to displays, or communication over the network like JAVA.

Database applications are usually partitioned into tiers. According to the image we can say it is ........-tier architecture.

• One

• Two

• Three

• Four

Which one is equivalent for "attribute" in Relational Model?

• column

• row

• table

• tuple

Which one is can NOT be said as a KEY type in SQL?

• Primary

• Foreign

• Unique

• Check

What is the meaing of Sigma (σ) operator in Relational Algebra?

• Select

• Project

• Union

• set difference

According to the image, what is the equivalent of SQL syntax of this Relational Algebra Query?

• SELECT * FROM instructor;

• SELECT * FROM instructor WHERE dept_name='Physics';

• SELECT dept_name FROM instructor

• SELECT * FROM dept_name WHERE instructor='Physics';

Relational Algebra is a __________ query language that takes two relations as input and produces another relation as an output of the query.

• Relational

• Procedural

• Structural

• Fundamental

Find the names of all instructors in the Physics department - Relational Algebra

• ∏name(instructor=“Physics” (instructor))

• σ name, dept_name(σ dept_name =“Physics” (instructor))

• ∏name(σ dept_name =“Physics” (instructor))

• ∏name, dept_name(σ dept_name =“Physics” (instructor))