Database Management Systems

Functional dependency is a relationship between attributes in a relation (table) within a database. It describes how the values of one attribute (or set of attributes) determine the values of another attribute (or set of attributes) in the same relation. In simpler terms, if knowing the value of one attribute uniquely determines the value of […]

NoSQL, which stands for “Not Only SQL,” is a term used to describe a wide range of database technologies that diverge from the traditional relational database model. Unlike SQL databases, which organize data into tables with predefined schemas, NoSQL databases are designed to handle large volumes of unstructured or semi-structured data in a distributed computing

A distributed database system comprises multiple interconnected databases stored across geographically dispersed locations, working together as a single, coherent unit. Unlike centralized databases, where all data resides on a single server, distributed systems partition data across nodes, providing improved scalability and fault tolerance. This architecture enables organizations to handle vast volumes of data, support high

Database Security encompasses a range of practices and measures designed to protect data from unauthorized access, corruption, and misuse. It involves implementing various layers of security protocols and mechanisms to fortify databases against potential threats. Authorization refers to the process of granting or denying permissions to users based on their identities, roles, or other attributes.

Backup refers to the process of creating copies of data to safeguard against data loss due to various factors such as hardware failures, human errors, software glitches, or malicious attacks. These copies are stored separately from the original data to ensure redundancy and resilience. on the other hand, Recovery involves restoring the database to a

Concurrency control refers to the mechanisms and techniques employed to manage simultaneous access to the database by multiple users or transactions. The primary goal is to ensure that transactions execute correctly and consistently, even when executed concurrently. This involves coordinating the execution order of transactions, managing locks on data items, and resolving conflicts that may

Deadlock is a scenario in DBMS where two or more transactions are indefinitely blocked, each waiting for a resource that the other transaction holds. Essentially, it’s a state of impasse where no progress can be made, leading to a standstill in the execution of transactions. In the below PDF we discuss about Deadlock in DBMS in detail in

In Database Management Systems (DBMS), a schedule refers to the chronological order or sequence in which transactions execute their operations over time. It represents a timeline of transactional activities, indicating when each transaction begins, performs its operations, and completes its execution. A schedule is essential for understanding how transactions interact and ensuring data consistency and

A Transaction refers to a logical unit of work performed on the database. This unit of work typically comprises one or more database operations, such as inserts, updates, or deletions. Transactions are executed as indivisible and atomic units, meaning they must either complete successfully and commit their changes to the database, or fail and leave

Query optimization is the process of enhancing the performance of database queries by selecting the most efficient execution strategy. It involves analyzing various potential query execution plans and choosing the one that minimizes resource consumption while maximizing throughput. Essentially, it’s about finding the fastest route to fetch the desired data from the database. In the