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 Cartesian product:
The Cartesian product operation does not need relations to union-compatible. The meaning of this is that the involved relations may have dissimilar schemas. Let R & S be relations that may have dissimilar schemas.
DEF: Cartesian product
The Cartesian product of relations R and S, denoted R X S, is the set of all probable combinations of tuples of the two operation relations. Every resultant tuple contains all the attributes of R and S.
The resultant relation has
Cardinality = (cardinality of R) * (cardinality of S); and
arity = (arity of R) + (arity of S).
For instance, in given table, STUDENT X MODULE is equal to
What is an entity relationship model? The entity relationship model is a set of basic objects known as entities and relationship between those objects. An entity is a thing or
Need for Multiple Access Paths In practice, most of the online information systems need the support of multi-key files. For example, consider a banking database application hav
Describe queries with complex types? The present extension of the SQL query language deal with the complex type Let us start with the simple example: Find the title and t
Economics: It is now usually accepted that it costs less to make a system of smaller computers with the equivalent power of a one large computer. It is more cost-effective to get s
How does a query tree represent a relational algebra expression? Ans: This includes transforming an initial expression (tree) into an equivalent expression (tree) that is
What is DataWarehousing? Subject-oriented, meaning that the data in the database is organized so that all the data elements relating to the similar real-world event or object
State as Location within a Program In this traditional approach, location of control inside a program totally defines the program state. Any finite state machine may be implem
Define hot swapping? Hot swapping permits the removal of faulty disks and changes it by new ones without turning power off. Hot swapping decreases the mean time to repair.
For every multivalued attribute 'A', we make a new relation R that contains an attribute corresponding to plus the primary key attribute k of the relation that shows the entity typ
Creation of Indexes Automatically: When a primary key or Unique constraint is show in a table definition then a unique index is formed automatically. Manually: User can
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