Database Basic concepts

1. Differentiate end user and naive user

End Users/Parametric Users − These users access the database from the front end with the help of a pre-developed application. They have little knowledge about the design and working of databases. Naive Users − These naive users are those users who don't have any database knowledge.

2. Foreign key

A FOREIGN KEY is a field (or collection of fields) in one table, that refers to the PRIMARY KEY in another table.

3. Difference between functional dependency and fully functional dependency

If all non-key attributes of table completely depends whole part of the primary key then this type of dependency is called fully functional dependency. While when all non-key attributes does not completely depends on primary key then this type of dependency is known as partial dependency(functional dependeny)

4. Key attributes and non-key attributes

As the name suggests key attribute will uniquely identify the entities whereas the non-key attributes would not be able to uniquely identify the entities. Attributes or fields that are selected for primary key known as key attribute while all other attributes or field are called non-key attribute.

5. Query optimization

The process of selecting an efficient execution plan for processing a query is known as query optimization.

6. Difference between table and view

A table is a database entity that stores data in the form of rows and columns. A view is a virtual table used to view or manipulate some parts of the table.

7. Normalization

Normalization is the process of organizing data in a database. It includes creating tables and establishing relationships between those tables according to rules designed both to protect the data and to make the database more flexible by eliminating redundancy and inconsistent dependency.

8.Database user and administrator

Database users are the persons who interact with the database and take the benefits of database while Database Administrators coordinate all the activities of the database system. They have all the permissions.

9. Database security

Database security refers to the range of tools, controls, and measures designed to establish and preserve database confidentiality, integrity, and availability.

10. Primary key

A PRIMARY KEY is a single column/field in a table that uniquely identifies each record in a database table.

11. Data and information

Data is a collection of raw facts and figures in the form of text, graphics, audio or video while processed form of data is called information. Data is input while information is output.

12. Data consistency

Data consistency is the accuracy, completeness, and correctness of data stored in a database. 

13. Mata data

Metadata is "data that provides information about other data", but not the content of the data, such as the text of a message or the image itself.

14. Composite key

A composite key, in the context of relational databases, is a combination of two or more columns in a table that can be used to uniquely identify each row in the table.

15. Data redundancy 

duplication of same data in multiple Tables of relational database is known as data redundancy. Its causes inconsistency of database.

16. Cardinality

Cardinality is the numerical relationship between rows of one table and rows in another. In other words number of instances/records of one table related to instances of of another table. Common cardinalities include one-to-one, one-to-many, and many-to-many.

17. DBMS

DBMS stands for DataBase Management System. Its is a collection of programs which are used to create and manage databases. ex Ms Access, MySQL etc

 18. Data integrity 

Data integrity is the overall accuracy, completeness, and consistency of data. Data integrity also refers to the safety of data in database by implementing different rules and constraints.

19. Data dictionary

A data dictionary in Database Management System (DBMS) can be defined as a component that stores the collection of names, definitions, and attributes for data elements that are being used in a database.

20. Alternate key

The keys that contain all the properties needed to become a Candidate Key are known as Alternate Keys.

21. Weak entity

In a relational database, a weak entity is an entity that cannot be uniquely identified by its attributes alone; therefore, it must use a foreign key in conjunction with its attributes to create a primary key. The foreign key is typically a primary key of an entity it is related to. 

22. Data isolation

In database systems, isolation determines how transaction integrity is visible to other users and systems. Is is database security policy.

23. Data automicity

Atomicity means that multiple operations can be grouped into a single logical entity, that is, other threads of control accessing the database will either see all of the changes or none of the changes.

24. Application programmer

Application Programmers also known as Back-End Developers, are computer professional users who are responsible for developing the application programs (C, C++, Java, PHP, Python, etc.) or the user interface so that other users can use these applications to interact with the database.

25. Repeating groups

When a field in a given row contains more than one value for each occurrence of the primary key, then that group of data items is called a repeating group. This is a violation of the first normal form, which does not allow multi-valued attributes.

26. Mutual dependency