SQL Server - Assignment PDF

Running head: SQL SERVER
SQL SERVER
Name of student:
Name of university:
Author’s note:

SQL SERVER1
Answer of question 1:
Normalisation: Normalisation denotes to the restructuring the relational database with respect
to a series of so-called normal forms for reducing the redundancy of data and improve the
integrity of data. The method of normalisation includes organising of the columns and the
tables of any database for ensuring the properly enforcing of the dependencies by the
integrity constraints of the database (Armbrust et al., 2015). It is completed with the
application of some formal rules by any process of synthesis or the decomposition. The major
objective behind using the normalisation is to redesign when extending the structure of the
database. A completely normalised database permits the extension of the structure for
accommodating new datatypes without altering the existing structure. This results in the
minimal effect on the applications that are interacting with the database. The removal of
redundancy prevents the deletion, insertion, and the errors of update, as the data is available
in only one attribute of a table in the database (Xin et al., 2013). The data residing in the
database is considered to be following one of the number of normal forms. Commonly, the
redundancy extent in the database is indicated by the normal data form. The ordering of the
normal forms follows a strict rule, which are:
1. 1st normal form
2. 2nd normal form
3. 3rd normal form
4. BCNF
Normalisation is required in a good database system for ensuring the integrity of data and
eliminate the redundancy of data.

SQL SERVER2
 Data redundancy: if the location of the data residing in the database is more than one
or the calculation of the data can be done from other items of data, then it is
considered to contain redundancy (Li & Manoharan, 2013).
 Data integrity: all the data residing in the database in consistent, and it also satisfies
all the integrity constraints.
The storing of data should be done once in a database and the storing of data that might be
calculated from any other data that is already in the database must be avoided. During the
normalisation process, the removal of redundancy must be done without breaking the
integrity rules of the data. If the redundancy is found in the database, then several problems
may arise when the operation of the database is done in normal form:
 When the insertion of data is done, the duplication of the data must be done
accordingly in every place where redundancy is found. As an instance, if two tables
exists in a database, and both the tables contains a column of employee name, then the
creation of a new employee entry requires the updating of both the tables with the
column employee name.
 When the modification of data is done in a database, if redundancy is found in the
data that is being changed, then all the versions of the data that is redundant should be
updated simultaneously (Bittorf et al., 2015). Therefore, in the example of employee
column, any alteration on the employee name should happen in both the tables
simultaneously.
Answer of question 3
Part (a)
Purpose of indexing in database