Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Explain nested relations?
Nested relations
The assumption of INF is a natural one in the bank examples we have considered.
However, not all applications are best modelled by INF relations.
The nested relational model is an extension of the relational model in which domains might be either atomic or relation valued.
We illustrate nested relations by an example from a library. Assume we store for every book the following in formations
Book title
Set of authors
Publishers
Set of keywords
We can see that if we describe a relation for the preceding information, several domains will be monatomic
Authors
Keywords
Complex types
Collection and large object types
Create table books(
...
Keyword-set setoff(varchar(20))
)
Structure types
Creation of values of complex types
E-R model uses this symbol to represent weak entity set ? A Doubly outlined rectangle symbol is used to represent weak entity set.
Increases efficiency : Data is stored close to most often used site, therefore retrieval would be faster. Also, data that is not required by local applications is not stored, there
What is B-Tree? A B-tree eliminates the redundant storage of search-key values .It permits search key values to appear only once.
why older data models are being replaced by new data models.
What is Trigger? Trigger: A database trigger is procedural code which is automatically executed in response to specific events on a particular table in a database. Triggers can
What three major types of actions includes databases? Briefly discuss these The three major types of actions including databases are: (i) Defining: It includes specifyin
Explain the challenges before an E-business management.
a publishing company produce scientific books on various subjects. the books are written by authors who specialize in one particular subject. the company employs editors who, not n
Normal 0 false false false EN-IN X-NONE X-NONE
Explain what is Aggregation? Aggregation: Aggregation is an significant concept in database design whereas composite objects could be modelled during the design of database a
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!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd