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 the conventions for displaying an ER schema as an ER diagram?
An E-R Diagram scheme might describe certain constraints to that the contents of a database must conform.
Mapping Cardinalities: Express the number of entities to that another entity can be related through a relationship. For binary relationship sets among entity sets A and B, the mapping cardinality must be one of:
1. One-to-one: An entity in A is related along with at most one entity in B, and an entity in B is related with at most one entity in A. 2. One-to-many: An entity in A is related along with any number in B. An entity in B is related with at most one entity in A. 3. Many-to-one: An entity in A is related with at most one entity in B. An entity in B is associated with any number in A. 4. Many-to-many: Entities in A and B are related along with any number from each other.
The suitable mapping cardinality for a particular relationship set depends on the real world being modeled. Cardinality ratios for binary relationships are represented on ER diagram through displaying 1,M, N etc. on the diamonds.
Existence Dependencies: if the existence of entity X depends on the existence of entity Y, then X is said to be existence dependent on Y.
Dirty Reads: T10 reads a value which is updated by T9. This update has not been committed and T9 aborts. T9 T10 Value of x old value = 200
What is Nested Queries explain in details? Nested Queries - A SELECT query could have subquery(s) in it. While a SELECT query having another SELECT query in it, is known as n
What is a value? A data value is used for identity. This form of identity is used in relational systems.eg: The primary key value of a tuple recognize the tuple.
Winfield is a small city with a population of 22,000 with buses serves three routes in Winfield and neighboring areas. As the city’s IT director, you have been asked to set up an i
Develop a database broker framework to implement a persistence mechanism for the domain objects involved in the use case dealt with in Question 2. a. Specify the attribute type
The cross-section of twisted pair The cross-section of each and every strand of the twisted pair is π/4 square mm. A 10-km length of this type of material, with two strands per
When are two schedules said to be view equivalent? Ans: Two schedules that is denoted as S and S' are said to be view equivalent if the subsequent three conditions are met
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
Draw entity relationship diagram for the following scenario. A university has many departments whereas each department belongs to that particular uni. That uni has also many bui
Consider a research paper submission process. The process starts when an author submits a draft research paper (the paper may have up to 3 authors) to the chair of the organizing c
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