Record based logical models, Database Management System

Assignment Help:

Record based Logical Models: Use records as the key data representation components

Examples:

Relational Model: It shows data as well as relationship between data in the form of tables.

Constraints are stored in a meta-data table. This is a very easy model and is based on a proven mathematical theory. This is the most usually used data base model.

Network Model: In this model data is shown as records and relationship as links. A easy network model example is explained in Figure . It shows a sample diagram for such a system. This model is a very good quality model as far as conceptual framework is concerned but is today not used in database management systems.


Related Discussions:- Record based logical models

Calculate the joint probability, Consider the following frequency counts o...

Consider the following frequency counts of some itemsets in a transaction database r : freq({A}, r) = 0.405 freq({B}, r) = 0.510 freq({C}, r) = 0.303 freq({A

Describe the two alternatives for specifying structural, Describe the two a...

Describe the two alternatives for specifying structural constraints on relationship kinds? Relationship kinds have certain constraints in which limit the possible combination o

Tables, does tables are called relations

does tables are called relations

Where and having clause in sql, WHERE and HAVING clause in SQL ? The WH...

WHERE and HAVING clause in SQL ? The WHERE clause is commonly used for implementing conditions on each tuple of the relation. The HAVING clause is used in combination along wi

What are the three types of data sources, What are the three types of data ...

What are the three types of data sources used with ODBC? An ODBC file data source is a file that can be shared between database users. An ODBC system data source is one that is

Write a short note on built in function in qbe, Write a short note on built...

Write a short note on built in function in QBE? Built in function in QBE: QBE involves various built in functions like AVG, MAX,MIN,SUM and CNT. We must prefix these operator

ERD, The entity type STUDENT has the following attributes: Student Name, Ad...

The entity type STUDENT has the following attributes: Student Name, Address, Phone, Age, Activity, and No of Years. Activity represents some campus-based student activity, and No o

Domain constraint, Domain Constraint It shows that each attribute in a ...

Domain Constraint It shows that each attribute in a relation has to contain an atomic value only from the corresponding domains. The data types associated with commercial RDBMS

Binary relationship, explain in details about one to one binary relationshi...

explain in details about one to one binary relationship

Determine candidate and primary key, A video rental company has several bra...

A video rental company has several branches. The data held on each branch is the branch address made up of street, city, state, and zip code, and the telephone number. Ea

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