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Comparing Two Different
Databases
By Jack Parsons
Purpose of Database 1
The purpose of this database
is to store the different
contact information regarding
each customer. This particular
database is a flat database.
This means that it only has
single table to store all the
information on.
The user contains a primary
key, the CustID, to identify
each separate customer
despite it being repeated to do
some customers having
multiple methods of being
contacted. The name of the
Found via Google Images
customer is listed across the next two columns. The third column contains the actually contact
information used to contact the customer while the final column contains what type of contact it
is. This would be used by any employees of the company that wished to contact their customers
Tools used by Database 1
This database potentially uses several different tools and techniques. First of all I believe it
uses the number data type for the CustID field to ensure that all entered information is a
number as all of the CustID entries with be numbers. It could also go further and use data
validation to further reduce potential mistake via the use a length check. Using a length check
means that a minimum amount of the numbers that can be enters will stop too few numbers
being entered. Not only that, but depending on the amount of customers of the company using
the database, they could also potentially limit the amount of allowed numbers to just 3 or 4.
You could also sort through the table using the CustID field to find out all the methods of
contacting a single customer. Not only that, but you could also sort through the method of
contact to find all methods of a particular kind. You could also use a query to find out all of this
information. Using a query can be more effective as it would only display the searched for
information and the use of a complex query would result in being able to look for multiple
things at the same time unlike sorting.
The use of a form could also be useful provided the CustID was already filled out as it would
allow the customer to fill in their own details and the details of how to contact them. This could
help reduce the demands on the time of the employees as they wouldn’t need to fill out the
information themselves and it could help reduce potential inaccuracy as the customers should
known their own details better than the employees.
Purpose of Database 2
Found via Google Images
The purpose of this database is to
store the information about the
books, the publisher and the
author. This particular database is
a relational database. This means
the information is stored across
multiple tables which are then
linked to each other. In this case,
the top table is linked to the
bottom table via the PubID field.
The middle table is linked to the
bottom table via the AuthorID
field. The top and middle tables
are indirectly linked with each
other due to both of them being linked to the bottom table. This database would be used by having
the user look for what information they already have, either the publisher, the author or book title,
and find the related infromation in the other two tables. The users would then be able to identify
the book, the author and the publisher. Users would mainly use this database to locate or identify
the book or its publisher or author.
Tools used by Database 2
This database uses several different techniques and tools to help with productivity, usability and
accuracy. For starters, this includes the use of primary keys and relationships between the
different tables. Each table as a different primary key, a PubID for each publisher, an AuthorID
for each author and a ISBN for each book. This allows a user to be able to identify each one with
ease. The primary keys are also essential to making to the relationships work as on the book
page, the publisher and author of each book is listed via their PubID and AuthorID respectively.
This means that each publisher and author can be clearly identify as a publisher would have
published multiple books and an author might have written multiple books.
Also tied into relationship function is the a potential usage of the query function. Once a
publisher’s PubID or an author’s AuthorID has been identified by the user, it allows the user to
perform a simple query for that particular PubID or AuthorID on the bottom entity. This allows
the user to identify all of the books either published by a publisher or all the books that were
written by an author. Another way do that is to use the filter function to search a field for a
particular PubID or AuthorID. You effectively get the same result from using either function and
I personally feel that which one of them is better depends on which function the user prefers to
use.
Tools used by Both
Databases
Several tools and techniques are used by both databases for the same purposes and pretty
much in the same manner. One of these techniques is data verification. By using data
verification, both databases can check for inaccurate data and replace it with the correct data.
This works by having people check the data that has been entered into the database against
correct copies of the data. They can also do this on a smaller scale as for example, on
Database 1 the employees of the company can ask the customers if their contact details are
correct.
Another tool that can be used by both databases is a list box. A list box is done by creating a
list contain different values that appears when the field is selected. This can be used by
Database 1 as it could give the options that are to be entered in the ContactType. This could
be limited to just those options in the list or could allow other values to be entered other than
those that are listed.
Another tool is using data types to make sure the correct type of data is entered. This means
that the only data that is allowed to be entered into a field is those that are part of that field’s
data type. For example, data type is used in Database 2’s AuthorBDay field to make sure that
the data entered is a date. It also used in Database 1’s CustID field to make sure only
numbers can be entered into that particular field
Strengths and Weaknesses
of Database 1
As a flat database, it has several advantages and disadvantages. Due to being a flat database, the
database has all of its information stored in a single location. This allows for the user to access all of
the information at once. This makes it easier to find information when the database is small. On the
other hand, it causes problems once the database has grown to a large size. Due to being so large,
information is hard to find on the database as it becomes jumbled up and disorganised.
Another disadvantage of having all its information on a single table is that it results in duplication of
data. This results in data being hard to keep up to date as the user has to update all of the data. If the
user fails to update a piece of data, it can cause problems as the information stored on the database is
now inconsistent and partially outdated. It can also cause problems as future users might not know
which copy of the information is the correct one. The previous user might have missed out a single
piece of data or only updated one part of the data.
An advantage of this particular database is that it’s easy to identify a method of contacting a customer
using the primary key (CustID). This means that as long as you know the CustID of the customer you
want to contact, you use this database with ease.
Another advantage of this database is that due to its specialised nature and purpose, it won’t become
inefficient as it become larges like with most flat databases as it stores only single piece of
information that any dulipication in data would happen regardless of whether is was on a flat or
relational database.
Strengths and Weaknesses
of Database 2
As a relational database, the second database has a multitude of advantages. The first is that
through the use of multiple tables, the different sets of data is efficiently stored as all of the
publisher details, the author details and the books details are store in their own tables. This
means that rather than searching a single table that contains all of the data, you just find the
table containing the relevant information. The use of relationships connects the tables within
the database and allows the user to be able to identify with ease the different publishers and
authors of the books. Another advantage of this database is that it doesn’t have duplicate
data, meaning that when data is updated, it can be done efficiently and effectively without
the worry of having outdated duplicate data within the database.
A disadvantage of this database is that it can be hard to understand is the user doesn’t
understand how databases work. Unlike with a flat database, where the data is all there on a
single table, this database requires knowledge of relationships within databases and how
primary keys work. This means that an inexperienced user would be unable to use this
database.
Another strength of relational database in general is that access to certain tables can be
limited. While that is exactly needed for this database as none of its tables had data that need
restricted access, it can be important for other relational databases.