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Database Articles
Page 116 of 547
Commercial Database
A Commercial Database is a paid database service designed for users who need access to large volumes of specialized information. These databases are subject-specific, containing vast amounts of curated data that individual organizations cannot afford to collect and maintain on their own. Access is provided through commercial links or subscription plans. Commercial Database Access Model Commercial Database Paid Access ...
Read MoreEnd User Database
An End User Database is a shared database specifically designed for end users who are not concerned with the underlying transactions, operations, or technical details. The end user interacts only with the final product − a software application or interface − and the database presents summarized, meaningful information for their use. Raw Operational Database SQL, Transactions, CRUD Data Processing & Aggregation End User Database Interface Dashboards, Reports, Simple Views ...
Read MorePersonal database
A Personal Database is a small, single-user database that is stored and managed on a personal computer. The data is collected and used by an individual or a small group of people, typically within the same department of an organization. Personal databases are designed for simplicity and ease of use, making them ideal for managing personal information, small projects, or departmental data without the complexity of enterprise-level systems. Characteristics Personal databases have several key characteristics that distinguish them from larger database systems − Single-user − Designed for one user or a small group at a time. Small size − ...
Read MoreEntity Relationship Participation in Database
In a relationship, the Participation Constraint specifies the existence of an entity when it is related to another entity. It is also called the minimum cardinality constraint and specifies the number of instances of an entity that can participate in a relationship type. There are two types − Total Participation and Partial Participation. Total Participation In total participation, each entity in the entity set must be involved in at least one relationship instance. No entity can exist without participating in the relationship. This is also known as mandatory participation. Example − Consider two entities Employee and Department related via the ...
Read MoreMultiple Relation Queries and JOIN Ordering
Multiple relation queries involve joining several tables to produce a result set. The order in which JOIN operations are executed can significantly affect query performance. Query optimization determines the most efficient execution plan by evaluating different JOIN orderings. Challenges The query optimizer must determine the most efficient execution plan considering join selectivity, data size, distribution, and available access paths. With n tables, there are n! possible join orderings, making optimal selection a complex process. Table A 1M rows Table B ...
Read MoreDifference between Primary key and Foreign key in Database
In a relational database, keys are the most important elements to maintain the relationship between two tables or to uniquely identify the data from a table. Primary key is used to identify data uniquely therefore two rows can't have the same primary key. It can't be null. On the other hand, foreign key is used to maintain relationship between two tables. The primary key of a table acts as the foreign key in another table. The Foreign key in a table helps enforce Referential Integrity constraint. Read this tutorial to find out more about Primary and Foreign keys and ...
Read MoreBinary Relationship in Database
A Binary Relationship is a relationship between two different entities in a database. It maps the role group of one entity with the role group of another entity, establishing how data in one table relates to data in another table. There are three types of cardinalities for binary relationships − One-to-One (1:1), One-to-Many (1:N), and Many-to-Many (M:N). One-to-One (1:1) In a one-to-one relationship, one instance of the first entity is mapped with only one instance of the second entity. The primary key of one entity is available as a foreign key in the other entity. This type of relationship is ...
Read MoreTernary Relationship in Database
In a Ternary Relationship, three different entities participate in a single relationship simultaneously. The relationship degree is 3. When determining cardinality, we consider it in the context of two entities relative to the third. Example: Mobile Manufacturing Company Consider a mobile manufacturing company with three entities − Mobile − The mobile models manufactured by the company. Part − Mobile parts which the company gets from suppliers. Supplier − Suppliers who supply mobile parts to the company. All three entities participate simultaneously in a SUPPLIES relationship ...
Read MoreOne-to-One Unary Relationship in DBMS
A One-to-One Unary Relationship (also called a recursive relationship) is an association within the same entity where one instance is related to exactly one other instance of the same entity type. This type of relationship creates a loop back to the same entity, allowing instances to be connected to other instances of their own type. Understanding One-to-One Unary Relationships In a one-to-one unary relationship, we have a single entity that participates in a relationship with itself. The key characteristic is that each instance can be related to at most one other instance of the same entity, and vice ...
Read MoreRDBMS terminologies
RDBMS (Relational Database Management System) uses specific terminologies to describe its components. These include Database, Table, Column, Row, and various types of keys. Let us see them one by one − Database A database is a collection of related tables. For example, a university database may contain tables like Student, Professors, Courses, etc. Table A table (also called a relation) is a collection of rows and columns that stores data about a specific entity. Here's an example of a Student table − ...
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