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Articles on Trending Technologies
Technical articles with clear explanations and examples
What is NoSQL and is it the next big trend in databases?
A NoSQL ("non SQL" or "non relational") database stores and retrieves data using models other than relational tables. NoSQL databases are structured as key-value pairs, documents, columns, or graphs − designed for large-scale data, high performance, and flexible schemas. Why NoSQL? Applications like Facebook, Google, and Amazon need to handle massive data volumes that traditional RDBMS struggles with. NoSQL allows adding new data fields without redesigning the entire schema − ideal for agile development. SQL vs NoSQL Example SQL requires predefined tables and schema changes for new features ? CREATE TABLE users (id INT ...
Read MoreDifference between DBMS and RDBMS
A DBMS (Database Management System) is software used to create, update, delete, and maintain a database with controlled access to data. An RDBMS (Relational Database Management System) is an enhanced type of DBMS based on the relational model, storing data in tables with defined relationships. What is a DBMS? DBMS stores data in the form of files using navigational or hierarchical structures. There is no relationship between data elements, so it does not support distributed databases. DBMS is often used in small organizations to deal with small amounts of data handled by a single user. Examples include file ...
Read MoreExamples of E-R model
The ER (Entity-Relationship) model represents real-life scenarios as entities. The properties of these entities are their attributes, and their connections are shown as relationships. ER models help visualize how data is structured in a database system. Hospital ER Model This ER model has three entities − Patient, Doctor, and Tests ? Patient ID (PK), Name Age, Visit_date Doctor ID (PK), Name Specialization Tests ...
Read MoreExtended Entity-Relationship (EE-R) Model
The Extended Entity-Relationship (EE-R) Model is a high-level data model that incorporates extensions to the original ER model to represent complex database requirements. In addition to basic ER concepts, EE-R includes − Subclasses and Super classes Specialization and Generalization Category or Union type Aggregation Subclasses and Super Class A super class contains common attributes shared by all its subtypes. Sub classes are groups of entities with unique attributes that inherit properties from the super class ? Shape ...
Read MoreHierarchical Database Model
A hierarchical model represents data in a tree-like structure where each record has a single parent. A sort field keeps sibling nodes in order. This model was designed for early mainframe systems like IBM's Information Management System (IMS), supporting one-to-one and one-to-many relationships. Data is structured as an inverted tree − a single root table at the top, with other tables as branches. Records are accessed by navigating down through the structure using pointers combined with sequential accessing. Agents Database Example The following diagram shows a typical hierarchical database ? ...
Read MoreOne-to-Many Relationship Model
In a "class roster" database, a teacher may teach zero or more classes, while a class is taught by one (and only one) teacher. In a "company" database, a manager manages zero or more employees, while an employee is managed by one (and only one) manager. In a "product sales" database, a customer may place many orders, while an order is placed by one particular customer. This kind of relationship is known as one-to-many. Why One-to-Many Cannot Be Represented in a Single Table If we begin with a table called Teachers and try to store classes taught, we ...
Read MoreEarly Database Models
A database model determines the logical structure of a database and defines how data can be stored, organized, and manipulated. Before databases were developed, the only way to store data was in file storage systems, which increased complexity as programmers had to perform complex parsing and relating operations to extract data. File Storage Complex, redundant Database Models Structured, ...
Read MoreCloud Databases
A cloud database is a database that has been optimized or built for a virtualized environment, deployed in a hybrid cloud, public cloud, or private cloud. Cloud databases offer the ability to pay for storage capacity and bandwidth on a per-user basis, provide scalability on demand, and deliver high availability. They also give enterprises the opportunity to support business applications in a software-as-a-service (SaaS) deployment. Cloud Database DB DB DB ...
Read MoreOperational Database
An operational database is a system designed to store information related to the day-to-day operations of an enterprise. Functional lines like marketing, employee relations, customer service, inventory management, and sales require such databases to maintain current and frequently accessed data. Operational databases are also known as OLTP (Online Transaction Processing) systems because they handle real-time transactions and support the ongoing operations of a business. Key Characteristics Real-time processing − Handle immediate transaction processing. High concurrency − Support multiple users accessing data simultaneously. Data integrity − Maintain ACID properties for reliable transactions. Normalized structure − Reduce data ...
Read MoreNoSQL Databases
NoSQL databases (Not Only SQL) are designed for large sets of distributed data. Some big data performance issues that are not effectively handled by relational databases are easily managed by NoSQL databases. They are very efficient at analyzing large-size unstructured data that may be stored across multiple virtual servers in the cloud. Types of NoSQL Databases NoSQL databases are categorized into four main types based on their data model − Document Store JSON-like documents MongoDB ...
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