What is DBMS?

What is a DBMS?

A DBMS (Database Management System) is software that lets you create, define, and change a database. It helps users store, process, and analyze data easily.

What are Database Model Types?

These are different ways to arrange and organize data in a database. Common types include relational, hierarchical, and network models.

What is an ER Model?

The Entity-Relationship model is a way to show a high-level picture of how data in a database is connected. It uses entities (things), attributes (their properties), and relationships (how they link).

What is an Extended ER Model?

This is a more advanced version of the ER model. It includes extra ideas like specialization, generalization, and aggregation to show complex data relationships more accurately.

What is an RDBMS Relational Database Management System?

An RDBMS (Relational Database Management System) is a type of DBMS that uses the relational model, where data is kept in tables (also called relations).

What are Codd's 12 Rules?

These are 13 rules (numbered zero to twelve) created by E. F. Codd that explain what a database system needs to do to be truly relational.

What is Relational Algebra?

This is a procedural query language. It takes tables as input and gives tables as output, using special operations to perform queries.

What is Relational Calculus?

This is a non-procedural query language based on mathematical logic. It describes what data you want, not how to get it.

What is converting ER Model to Relational Model?

This is the process of turning an ER diagram into a set of tables in a relational database.

What are Database Keys?

These are an attribute or a group of attributes that uniquely identify each row in a table.

What is Database Normalization?

This is the process of organizing columns and tables in a relational database to reduce repeated data and improve data accuracy.

What is First Normal Form (1NF)?

The first step in normalizing a database. It requires that all table columns have single, indivisible values, and every row is unique.

What is Second Normal Form (2NF)?

A database is in 2NF if it's already in 1NF and all its non-key attributes fully depend on the primary key.

What is Third Normal Form (3NF)?

A database is in 3NF if it's in 2NF and all its attributes depend directly only on the primary key (no dependence through another attribute).

What is Boyce-Codd Normal Form (BCNF)?

A stricter version of 3NF. For a table to be in BCNF, if one attribute determines another, then the first attribute must be a superkey.

What is Fourth Normal Form (4NF)?

A stage of database normalization where there are no hidden relationships between multiple non-key attributes.

What is Fifth Normal Form (5NF)?

A stage of normalization that handles complex dependencies to further reduce redundancy in relational databases.

What is SQL?

SQL (Structured Query Language) is the standard language used to manage and change data in relational databases.

What are DML Commands?

DML (Data Manipulation Language) commands are used to manage data inside database objects. (Examples: INSERT, UPDATE, DELETE).

What are DCL Commands?

DCL (Data Control Language) commands are used to manage who can access data in a database. (Examples: GRANT, REVOKE).

What are TCL Commands?

TCL (Transaction Control Language) commands are used to manage transactions in the database. (Examples: COMMIT, ROLLBACK).

What are SQL Clauses (WHERE, LIKE, ORDER BY, GROUP BY, HAVING)?

These are parts of SQL queries used to filter, sort, and group data to get specific results from the database.

What is SQL JOIN?

A command used to combine rows from two or more tables based on a common column they share.

What are SQL Views?

A virtual table that is created from the result of an SQL statement. It looks and acts like a real table but doesn't store data itself.

What is PL/SQL?

PL/SQL (Procedural Language/SQL) is an extension of SQL created by Oracle for their database, adding programming features like data types, procedures, and cursors.

What is MongoDB?

MongoDB is a popular NoSQL database that stores data in flexible documents, similar to JSON. It's often compared to RDBMS and used with languages like Java.

What are some of the most popular DBMS used by companies?

Some of the most popular DBMS used by companies include MySQL, Oracle Database, Microsoft SQL Server, PostgreSQL, Snowflake and more. These systems provide tools for data management and retrieval.