Relational Database Model
A high level data model serves the database designer by providing a conceptual framework in which to specify, in a systematic fashion, what the data requirements of the database users are, and how the database will be structured to fulfill these requirements.
structural independencesimplicityad-hoc query capabilityeasy to designsecurity controlnon procedural access language
A row of a table in relational model is known as tuple - is the easy answer. A tuple is a collection of elements that relate to one another : T = R(e1, e2, ... , en). One can view a collection of similar relations, R, as a table, where the elements of same category are projected underneath one another, and ordered as is suited for the table view. When implementing a relational database, the tuples can be spread all over in a way that suits those that make the storage system, and enables fast retrieval and manipulation of them. So, unless you specify the sorting - "Collating Sequence" of the table, you can expect a new ordering every time you view the table. The elements in the relations are bound together in the same way as rows in a table - but some relations may have more elements - "columns" and really belong to other tables - but is "projected" into the view you see as a table.
The model's main function is to help us understand the complexities of the real-world environment. Within the database environment, a data model represents data structures and their characteristics, relations, constraints, and transformations. Good database design uses an appropriate data model as its foundation. Plus, a data model provides a blueprint of the data that is required for a functional system.
Relational Database Model
A Relational database management system (RDBMS) is a database management system (DBMS) that is based on the relational model as introduced by E. F. Codd. Most popular commercial and open source databases currently in use are based on the relational model. A short definition of an RDBMS may be a DBMS in which data is stored in the form of tables and the relationship among the data is also stored in the form of tables.
Access can use a relational model of a database design.
One of the advantages of a relational database model is that the broken keys and records and the data complexity are usually simplified. The disadvantage of the relational database model is that it requires sophisticated processing power which is very costly.
AnswerMySQL, like most modern Database Management Systems is based on the relational model. So it is a RDBMS (Relational Database Management System).
Relational model of database is a good way to represent the database. Also network data model and hierarchical model can be used depending on the requirements.
The Relational Database Management System was based on a good model. It is based on first-order predicate logic which was discovered in 1969 by a man named Codd.
AdvantagesConceptual simplicityVisual representationEffective communicationIntegration with the relational database model
1. Relational Model : Newer database model; Network Model - Older database model 2. The network model structures data as a tree of records with each record can have multiple parent and child records, forming a lattice structure. The basic data structure of the relational model is the table, where information about a particular entity (say, an employee) is represented in columns and rows 3.The relational model has strong mathematical foundation with set theory and predicate logic. Network Model has no strong mathematical background. 4. Relational model is the most flexible of the database models. Network model is not very flexible. 5. Relational model has widespead use. Network model has limited use.
fuzzy database manages the uncertainty and vagueness associated with either entities, attributes and relationships. this can be implemented in relational database model (fuzzy extension) or using object oriented databse model.
Ted Codd invented the relational model for database management.
A constraint between two sets of attributes is known as functional dependency in relational database. Determination of functional dependencies is vital in database denormalization, normalization and relational model.