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 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.
What is recursive closure? Why is it not possible to describe this operation in relational algebra? Recursive closure is applied to recursive relationship. An instance of rec
he SQL query that will return the order number, quantity ordered, price each and total cost of an order (quantity * price each) from the order details table. Label the calculated c
Define Sequence A sequence is a set of integers 1, 2, 3 that are generated in order on demand. Sequences are regularly used in databases because lots of applications require ev
(a) Why did SAP introduce the extended star schema?
Define the Query optimisation The query parser commonly generates a standard initial tree to correspond to an SQL query, with no doing any optimization. Such type of a canonica
Failure Controlling Methods: Failures can be handled using different recovery methods that are talk about later in the unit. But the first question is doing we really require recov
Submission Requirements All answers must be computer generated (including text and diagrams). The hand-in version must include a header page (or with sufficient space)
What is SQL Profiler? SQL Profiler is a graphical tool that permits system administrators to monitor events in an instance of Microsoft SQL Server. You can capture and save dat
What is Multivalued Attribute? Multivalued Attribute - Multivalued attribute might have more than one value for an entity. For instance, PreviousDegrees of a STUDENT.
While sorting field groups we cannot use more than one key field False.
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