Database Concepts Test - 3

In SQL, the relation is represented by a table, and a table is a collection of rows and columns. Therefore the collection of rows &columns is called the table, whereas a table is known as the relation in the SQL. So in a relation (or we can say table), rows are called the tuples. So, the correct answer will be tuples.

In general, the term "data "refers to the row facts and figure, whereas the information referred to as the data, which is really important for someone or a particular person. Therefore the correct answer is C.

In data manipulation language, the command like select, insert, update, and delete is used to manipulate the information (or data, records), for example create a table, update table delete table, etc. Therefore the correct answer is C.

Cardinality refers to the number of tuples of relation because cardinality represents the number of tuples in a relation.
To understand it in more detail, consider the following given example:
Suppose we have a relation (or table) that contains 30 tuples (or Rows) and four columns, so the cardinality of our relation will be 30.

In specialization, the top-down approach is used, and it is apposite to the generalization.
In the specialization, the higher-level entity can be divided into sub lower entities. It is generally used for identifying the subset of an entity set which share the distinguishing characteristics.
To understand it more clearly, consider the following example:
Suppose you have an entity, e.g., A vehicle. So through the specialization, you can be divided further into sub-entities like two-wheelers and four-wheelers. Therefore the correct answer is C.

The Data definition language is generally used to maintain or define the structure of the database. For example, creating a table, drop table, alter table. In short, we can say that the command of data definition languages is used to work on the table 's schemas inside the database.

In a database, the number of rows inside a table is known as tuples, and if we further divide those tuples (or rows) into those fields, they become the domains. So the correct answer will be B.

The bottom-up approach is used in the generalization. The several lower-level sub-entities are grouped together to make an individual higher-level entity. In short, we can say that it is totally the opposite of specialization. To understand it more clearly, consider the following example:
Example: Suppose you have several lower entities like bus, car, motorbike etc. So, in order to make a more generalize (or higher level ) entity, you can combine them under a new higher-level entity such as a vehicle.

In the database, the number of rows inside a table is called the tuples, and the numbers of columns are known as the attributes. Therefore the correct answer is C.

The term "TCL "refers to the Transaction Control Language, which is another language just like the "DDL "and "DML ". The commands like commit, save point, rollback come under the TCL used to control the transactions. Therefore the correct answer will be D.

To fetch data from the database management system, generally, the "select "statement is used. Therefore, the Data Manipulation Language is used in the application programs while requesting the data from the database management system.

The column inside the table is called the attribute, and the total number of attributes inside the table is called the degree. So, here as we can see, degree refers to the number of attributes in a relation. Therefore the correct answer is C.

The Transaction Control Language is used while working with the transactions. To save any transaction permanently into the database generally, the "commit "command is used, by which any changes get reflected permanently into the database, and they become irreversible.

To removing( or deleting) a relation, the "drop "command is used instead of delete because here we are working on the objects of the database. So, to maintain the objects of a database, the Data definition language is used. Therefore the "drop "command is used to delete a relation form a database instead of using the "delete "command.

To delete an existing row in a table the generally, the "delete "command is used. The "delete "command is one of the commands that belong to the Data manipulation language.