Database Concepts Assignment 1 - Database Essay Example

The two parts in this assignment will contribute equally to your grade and will be evaluated separately.

Part 1: Database Concepts
Imagine that a countryside inn maintains its data in flat files on a file system - Database Concepts Assignment 1 introduction. To assist in reserving rooms and booking guests, the innkeepers use a custom application that accesses these flat files. The innkeepers sometimes access the files directly. With this scenario in mind, address each of the topics below.

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Topic 1: The Advantages of Database Management Systems
Identify and describe several advantages that a database system would offer the inn over their current data management solution.

The purpose of the DBMS is to service between users’ applications and database. This way of accessing to data through the DBMS brings several advantages. First of all, it supports multiple user access at the same time, which helps to update data just in time. DBMS provide better security and integrity to the stored data, because the DBMS stands at the gates of access where it helps to enforce security policy. It reduces data inconsistency where the same data may display in different locations. It also supports quick requests in query such that ad hoc query and responses almost immediately. As a result, it positively effects to make decisions.

Increases end user productivity as well.

Topic 2: Structural Independence
Database systems exhibit structural independence, which occurs when the way that applications and users operate with the database is independent of how the data is actually stored in the file system or other storage device. Explain why structural independence is important to the innkeepers.

Structural independence when we can change structure of stored data without affecting to access of user’s applications. It is essential, otherwise in case of dependency there would be need to make all necessary adjustments to
keep the same type access that the users have.

Topic 3: Problems with Data Redundancy
Data redundancy occurs when the same data is duplicated in different parts of a data management system in such a way that the duplicates are unnecessary and the duplicates can become inconsistent. Identify and explain how the inn’s current data management solution could exhibit the three kinds of data anomalies described in the textbook.

Data Redundancy comes to the scene when necessary changes weren’t made successfully. There are: Update anomaly as an example for late checking out for room #5 where it might affect to the other rows where room #5 exists. Insertion anomaly, sometimes in order to make a room available inn needs to enter fake gust data to make room appear in the system, which may cause data inconsistency. Deletion anomaly, if inn decide to delete a room it may cause to disappear data information of guests as a result their bills.

Topic 4: Five Major Components of a DBMS
Our Coronel, Morris and Rob text describes database systems as having five major components: hardware, software, people, procedures, and data. If the inn were to adopt a database management system, describe ways in which people would interact with and be responsible for the hardware, software, procedures, and data.. You don’t need to try to provide an exhaustive list, because that would be voluminous, but only an indication that you have thought about how people would be responsible for and interact with each of the other four components.

Hardware is equipment, which handles data such as servers, workstations where users can get access to the data and make operations. As an example of interacting can be a system administrator who is maintaining the whole system. Software is basically it’s a huge set of instructions to the machines, servers and workstations work and do the job. People as specialists interact actively to make this whole system work properly. Procedure is also play important role in DBMS. It can be compared to the Legal laws for citizens where it helps to have discipline. As an example of
interaction is database administrator who interacts with people in daily basis. Data is a raw material and needs to be collected in proper way where later on the information can be boils down. The person who responsible is Data Base designer. Part 2: Converting a Spreadsheet to a Database

You might encounter something akin to the table below in a spreadsheet or file-based application.

First
Last
ID
HoursWorked
GrossPay
Withholding
NetPay
PayDate
Roger
McHaney
1
38.5
$561.56
$112.31
$449.25
10/23/2012
Roger
McHaney
1
38.5
$561.56
$112.31
$449.25
1/17/2012
Telly
O’Grady
2
30
$489.06
$97.81
$391.25
3/1/2012
Telly
O’Grady
2
30
$489.06
$97.81
$391.25
2/22/2012
Telly
O’Grady
2
20
$326.04
$65.21
$260.83
3/6/2012
Telly
O’Grady
2
44.5
$725.44
$145.09
$580.35
1/21/2012
Grant
Brikestein
3
18
$408.60
$81.72
$326.88
10/23/2012
Alarry
Abu
4
40
$728.80
$145.76
$583.04
1/17/2012
Betty
Marygrade
5
35
$792.40
$158.48
$633.92
1/17/2012
Samuel
Timod
6
40
$927.20
$185.44
$741.76
1/17/2012
Samuel
Timod
6
40
$927.20
$185.44
$741.76
1/24/2012
Imagine that you want to convert this to a relational database. Answer the
following questions, which are progressively more difficult: 1. How many records does this file contain?
It contains 11 records.
2. How many fields are there per record?
It contains 8 fields.
3. What are the field names?
The names are: First, Last, ID, Hours Worked, GrossPay, Withholding, NetPay, PayDate. 4. What do the records in this table probably represent?
It describes employees’ payments with working hour’s information. 5. Is there data redundancy in the table? If so, describe it. Yes, there is a record of one employee where appears several times Telly O’Grady is example of it. 6. Does this table contain data that is part of different entities? If your answer is “yes”, identify and briefly describe the entities. No it does not.

7. Are there any fields you would add when converting this spreadsheet to a database? If your answer is “yes”, identify each field then briefly describe the reason why you would choose to add it.

ID
HoursWorked
GrossPay
Withholding
NetPay
PayDate
1
38.5
$561.56
$112.31
$449.25
10/23/2012
1
38.5
$561.56
$112.31
$449.25
1/17/2012
2
30
$489.06
$97.81
$391.25
3/1/2012
2
30
$489.06
$97.81
$391.25
2/22/2012
2
20
$326.04
$65.21
$260.83
3/6/2012
2
44.5
$725.44
$145.09
$580.35
1/21/2012
3
18
$408.60
$81.72
$326.88
10/23/2012
4
40
$728.80
$145.76
$583.04
1/17/2012
5
35
$792.40
$158.48
$633.92
1/17/2012
6
40
$927.20
$185.44
$741.76
1/17/2012
6
40
$927.20
$185.44
$741.76
1/24/2012
I would divide this table to try avoiding redundancy in last and first name columns and save additional space. Also it should help retrieve more adequate data in case if we need to see person’s salary.

8. Are there other problems you would you need to address in converting this data to a relational database? If your answer is “yes”, identify and briefly describe each problem. Besides redundancy I don’t see other problems.

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