Explain record based logical models, Database Management System

Assignment Help:

Explain Record Based Logical Models?

Record-Based logical Models: Also define data at the conceptual and view levels. Unlike object-oriented models, are used to state overall logical structure of the database, and gives a higher-level description of the implementation. Named so since the database is structured in fixed-format records of various types. Each record type defines a fixed number of fields, or attributes. Each field is commonly of a fixed length (this simplifies the implementation). Record-based models do not involved a mechanism for direct representation of code in the database. Separate languages related along with the model are used to express database queries and updates. The three most widely-accepted models are the relational, network, and hierarchical.


Related Discussions:- Explain record based logical models

Define multivalued dependency, Define multivalued dependency.  What do unde...

Define multivalued dependency.  What do understand by trivial multivalued dependency?  Ans: A multivalued dependency is a full constraint among two sets of attributes in a rela

State the definition of association, State the definition of association ...

State the definition of association An association is a structural relationship which specifies that objects of one thing are connected with objects of another. In UML, asso

What is meant by physical blocks, What is meant by Physical blocks? The...

What is meant by Physical blocks? The input and output operations are completed in block units. The blocks residing on the disk are referred to as physical blocks.

Wait-die scheme -deadlock prevention, Wait-die" scheme : The idea is based ...

Wait-die" scheme : The idea is based on non-preventive method. It is based on a simple rule:                                 If Ti requests a database resource that is held by T

What is outer join, What is Outer join?  They can be employed while we ...

What is Outer join?  They can be employed while we want to keep all the tuples in R, or all those in S or all those in both relations in the result of the JOIN in spite of of w

Prove that a relation which is 4nf must be bcnf, Prove that a relation whic...

Prove that a relation which is 4NF must be BCNF.   Ans Let R be in 4NF.  Suppose it is not in BCNF.  Hence, there exists an FD X→Y in R such that x is not a super key. Although

Explain the concepts of relational data model, Explain the concepts of rela...

Explain the concepts of relational data model? Relational Data Model - The relational model was first introduced through Prof. E.F. Codd of the IBM Research in the year 1970

What is normalization, What is normalization? It is a method of analysi...

What is normalization? It is a method of analysing the given relation schemas based on their Functional Dependencies (FDs) and primary key to attain the properties (1).Minim

DISTIBUTED DATABASE, Define physical image of a global relation at a site

Define physical image of a global relation at a site

Equi join-table handling, Equi Join: A join in which the joining condition...

Equi Join: A join in which the joining condition is based on equality among values in the common columns. Common columns show (redundantly) in the result table. Let us Consider th

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd