Explain algorithm of er to relational mapping, Database Management System

Assignment Help:

Explain algorithm of ER To Relational Mapping ?

ER-to-Relational Mapping Algorithm:

1) Step 1: Mapping of regular entity types: For each strong entity type E, form a relation T which involves all the easy attributes of a composite attribute.

2) Step2: Mapping of weak entity types: For each weak entity type W along with owner entity type E, create relation R and involve all easy attributes (or simple components of composite attributes) of W as attributed of R. In addition, involves as foreign key attributes of R, the primary key attribute (s) of relation(s) which correspond to the owner(s) and the partial key of the weak entity type W, if any.

3) Mapping of relationship types: form a relation R, for relationship along with primary keys of participating relations A and B as foreign keys in R. Further to this, any attributes of relationship become an attribute of R also.

4) Mapping of multivalued attributes: For every multilvalued attribute A, form a new relation R. This relation R will involve an attribute corresponding to A, plus primary key attribute K-as a foreign key in R-of the relation which represents the entity category or relationship type that has A as an attribute.


Related Discussions:- Explain algorithm of er to relational mapping

Give the general form of sql query, Give the general form of SQL query? ...

Give the general form of SQL query? Select  A1, A2............., An From  R1, R2..............., Rm Where  P

Oracle, I have 10+ yrs exp in oracle Sql ,Pl/SQl,Forms ,Reports. I am exper...

I have 10+ yrs exp in oracle Sql ,Pl/SQl,Forms ,Reports. I am expert in assignements & Online tutoring so i want to join you. Please guide me. Thanks Brajesh Shukla +91 9899641535

Creating a view-data control, Creating a view: A query can be embed...

Creating a view: A query can be embedded within the CREATE VIEW STATEMENT A query can have complex select statements containing join, groups and sub- queries A quer

Name the metrics for selecting top algorithm, Name the metrics for selectin...

Name the metrics for selecting top algorithm There are a number of metrics for selecting top algorithm: i) Computational complexity: Computational complexity refers to eff

Explain the utilities which help the dba to manage database, Explain the ut...

Explain the utilities which help the DBA to manage the database? Every DBA uses database utilities to maintain and control their databases. But there is a lot of confusion wit

Explain what is to be done during defining problem statement, Briefly expla...

Briefly explain what is to be done during defining problem statement. To define Problem Statement of a system, define what is to be done and how you can go to implement that. Y

Describe the relational model, a) Distinguish between ‘database' and ‘Data...

a) Distinguish between ‘database' and ‘Database Management Systems (DBMS)'. b) List and briefly describe five potential benefits of the database approach compared to conventio

Determine the operation that do not participate to be union, 1. Which relat...

1. Which relational algebra operations do not need the participating tables to be union-compatible? Ans: Join is the relational algebra operations that do not need the particip

What is bcnf boyce-codd normal form, BCNF Boyce-Codd Normal Form A rel...

BCNF Boyce-Codd Normal Form A relation schema R is in BCNF if it is in 3NF and accepts an additional constraint that for every FD X A, X has to be a candidate key. If a relati

Explain the term- periodic recomputation, Explain the term- Periodic recomp...

Explain the term- Periodic recomputation Periodic recomputation:  Base values are often updated in bunches. Sometimes, it is possible to just recompute all derived attributes p

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