Write short note on data models, Database Management System

Assignment Help:

Write short note on Data models?

Data models: A data model is an abstract model which elaborates how data is represented and accessed. The term data model has two commonly accepted meanings:

• A data model theory that is a formal description of how data may be structured and accessed.
• A data model instance that is applying a data model theory to create a practical data model instance for a few particular application.


Related Discussions:- Write short note on data models

Give example of relational schema, An instance of relational schema R (A, B...

An instance of relational schema R (A, B, C) has distinct values of A including NULL values. then A is a candidate key or not? If relational schema R (A, B, C) has distinct val

Problems of concurrent transactions-lost updates, Lost Updates : Suppose th...

Lost Updates : Suppose the two transactions T3 and T4 run simultaneously and they happen to be interleaved in the following way (suppose the initial value of X as 10000):

Estimate the transaction states, Suppose an instruction takes 1 nanosecond ...

Suppose an instruction takes 1 nanosecond to execute (on average), a page fault takes 20 microseconds of processor time, and it takes 300 microseconds of disk time to read or write

Write a short note on temporary tables, Write A short note on temporary tab...

Write A short note on temporary tables? Temporary Tables - Temporary tables exists solely for a particular session, or whose data persists for the duration of the transaction

Explain the two types of participation constraint., Explain the two types o...

Explain the two types of participation constraint. 1. Total: The participation of an entity set E in a relationship set R is said to be total if each entity in E participates i

Generalization and specialization, design a generalization specialization h...

design a generalization specialization hierarchy for a motor vehicle sales company. the company sells motorcycles, passenger cars, vens and buses.

List the sql domain types, List the SQL domain Types? SQL supports the ...

List the SQL domain Types? SQL supports the following domain types. 1) Char(n) 2) varchar(n) 3) int 4) numeric(p,d) 5) float(n) 6) date.

What is candidate key, What is candidate key? Candidate Key - A candi...

What is candidate key? Candidate Key - A candidate key of an entity set is a minimal superkey, which uniquely identifies each row in the relation.

What is storage manager, What is storage manager? A storage manager is ...

What is storage manager? A storage manager is a program module that gives the interface among the low level data keeps in a database and the application programs and queries su

What is disadvantages of dbms, What is Disadvantages Of DBMS ? 1. Cos...

What is Disadvantages Of DBMS ? 1. Cost of Software and Hardware and Migration - A important disadvantage of the DBMS system is cost. 2. Reduced Response and Throughpu

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