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!
Multi-Key File Organisation
In this part, we will introduce two basic file Organisation schemes that permit records to be accessed by more than one key field, therefore, allowing multiple access paths each having a dissimilar key. These are known as multi-key file Organisations. These file organisation methods are at the heart of database execution.
There are numerous methods that have been used to execute multi-key file Organisation. Most of these methods are based on building indexes to provide direct access by the key value. Two of the commonest methods for this Organisation are:
Let us talk about these methods in more detail. But first let us talk about the need for the Multiple access paths.
Special comparison operator used in where Clause a. between. ...and...It gives range among two values (inclusive) Example: SELECT ENAME, SAL FROM EMP WHERE SAL BETWE
Q. Explain the terms key constraints participation constraints and mapping caradinalities in ER model. Participation Constraints : The participation of an entity set E i
The indices are accumulated in the index files. The data is accumulated in the data files. Indices give fast access to data items. For example, a book database may be managed in th
Define multivalued dependency. What do understand by trivial multivalued dependency? Ans: A multivalued dependency is a full constraint among two sets of attributes in a rela
Set Difference If R1 and R2 are two union compatible relations or relations then result of R3 =R1- R2 is the relation that have only those tuples that are in R1 but not in R2.
What is Conceptual Schema? Conceptual Schema - Conceptual schema elaborates the structure of the overall database for a community of users. It hides the details of physical sto
Write short notes on relational model The relational model uses a collection of tables to show both data and the relationships between those data. The relational mo
Explain three main attributes of data.
What are the advantages of creating a table from existing table?
Convert the following ER - diagram (Entity Relationship Diagram) into a relational database (the primary keys are underlined): Ans: The relational database schema f
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