SOFTWARE ENGINEERING MANAGEMENT

The DBMS I have chosen to download is MySQL.

tables_in_mondial

Show columns from borders;

Show columns from city;

Select count(*) from city;

Show columns from continent;

Select count(*) from continent;

Show columns from country;

Select count(*) from country;

Show columns from desert;

Select count(*) from desert;

Show columns from economy;

Select count(*) from economy;

Show columns from encompasses

Select count(*) from encompasses;

Show columns from ethnicgroup;

Select count(*) from ethnicgroup;

Show columns from geo_desert

Select count(*) from geo_desert

Show columns from geo_estuary

Select count(*) from geo_estuary

Show columns from geo_island

Select count(*) from geo_island

Show columns from geo_lake

Select count(*) from geo_lake;

Show columns from geo_mountains

Select count(*) from geo_mountain;

Show columns from geo_river

Select count (*) from geo_river

Show columns from geo_sea

Select count(*) from geo_sea;

Show columns from geo_source

Select count(*) from geo_source

Show columns from island

Select count(*) from island;

Show columns from islandin

Select count from islandin

Show columns from ismember

Select count(*) from ismmember;

Show columns from lake

Select count(*) from lake

Show columns from language

Select count(*) from language

Show columns from located

Select count(*) from located

Show columns from mergeswith

Select count(*) from mergeswith

Show columns from mountain

Select count(*) from mountain

Show columns from mountainonisland

Select count(*) from mountainonisland

Show columns from organization

Select count(*) from organization

Show columns from politics

Select count(*) from politics

Show columns from population

Select count(*) from population

Show columns from province

Select count(*) from province

Show columns from religion

Select count(*) from religion

Show columns from river

Select count(*) from river

Show columns from sea

Show count(*) from sea

Online information versus databases: What do we mean by the word "database"?

A database is a collection of data, where it is all structurally organized and classified so as to allow better processing of the information, in the future. Database information are organised from records and each record contain fields. Records are the title of what describes the data and fields is the data itself. Data is presented in a way, where, you would just have to look the fields and the information in the record to know what is needed to know.

An online information can be presented in a essay form, however, it cannot be compared a database as the information is presented in a different form. An essay describes the information in a way where you would have to read the entire line of the paragraph or the page in order to know how the information is classified or organized.

Example B: "There are three students enrolled on this course: Chiang, who is 23 years old; Kristina, aged 22; and Patrice, 28."

By looking at example A, you can easily tell the ages of Chiang, Kristina and Patrice by finding their name and looking at their age which matches their name. If you were to search Kristina’s name at random, you would be able to find her age easily. By looking at the database, it is shown that there are only 3 entries. However, in example B, u will have to read that there are only 3 students in the course. If a search were to be done for Kristina’s name in example B, it would have to go through the line and find out Chiang’s age first before moving on to Kristina.

Suppose that a database consists of 10 main tables, each with an average of 500,000

rows, with each row having an average of 8 numeric or alphanumeric fields (telephone

numbers, product codes, prices, quantities, etc), with each field having an average

width of eight digits or characters. Assume that all of this data, at some point, was

entered by human beings into a computer system using a keyboard. How many

characters or digits will be entered into this database?

10 x 500,000 x 8 x 8 = 320,000,000 characters

Assuming the very best (lowest) error rate mentioned in the Klemmer [1962] paper for

trained data entry operators, and assuming that there is no computerized method of

trapping erroneous data entry, how many characters or digits will be entered

erroneously? How many will be entered erroneously, assuming the

less-optimistic error rate cited by Baddeley & Longman [1973] for entering mail codes

(after correction)? Show your calculations.

320,000,000 x 0.02 = 64,000 errors will be entered erroneously (Klemmer [1962] paper)

320,000,000 x 0.5% = 1,600,000 errors will be entered erroneously.

Use the Luhn algorithm (by hand) to decide which of the following credit card numbers

are valid and which are not:

(1) 4657-4686-6987-0760 (NOT VALID)

(2) 4658-4686-6987-0760 (NOT VALID)

(3) 4659-4998-6988-0760 (NOT VALID)

(1) 4657-4686-6987-0760

8+6+1+0+7+8+6+1+6+6+1+2+9+1+6+7+0+7+1+2= 85 + x

(however x = 0, which does not make the sum a multiple of 10, thus the credit card number is not valid .)

(2) 4658-4686-6987-0760

8+6+1+0+8+8+6+1+6+6+1+2+9+1+6+7+0+7+1+2= 86 + x

(however x = 0, which does not make the sum a multiple of 10, thus the credit card number is not valid .)

(3) 4659-4998-6988-0760

8()+6+(1+0)+9+(8)+9+(1+8)+8+(1+2)+9+(1+6)+8+(0)+7+(1+2) = 95 + x

(however x = 0, which does not make the sum a multiple of 10, thus the credit card number is not valid .)

1. Entity Integrity Constraint states that no primary key can be null (M.Urse 1999)

2. Attribute Integrity Constraint are constraint applied to all value of any attribute / column specified in the table.

CREATE TABLE Country

(Name VARCHAR2(40) NOT NULL UNIQUE,

Code VARCHAR2(4) CONSTRAINT CountryKey PRIMARY KEY,

Capital VARCHAR2(40),

Province VARCHAR2(40),

Area NUMBER CONSTRAINT CountryArea

CHECK (Area >= 0),

Population NUMBER CONSTRAINT CountryPop

CHECK (Population >= 0));

3. Referential Integrity refers to any data shared between tables must remain consistent.

Referential integrity is not enforced in this database.

Data

1. The Prancing Ponies stable keeps several dozen horses, and employs several grooms to look after them. Each groom looks after several horses. (But no horse is looked after by more than one groom.) For example, Sarah looks after Max, Jasper, Pongo and Zip. Michael looks after Swifty and Coco.

Groom =>> Horse

Horse =>Groom

2. The Happy Horsies stable also has several grooms, and several horses. In

this stable, each groom is assigned several horses to look after, but grooms can also ‘share’ horses. That is, two or more grooms may look after the same horse. (This allows grooms to have time off.) So, for example, Rosa looks after Lightning, Plod, and Streak. Clara looks after Plod, Streak, and Firewind. Jon looks after Lightning and Firewind.

Groom =>> Horse

Horse =>> Groom

3. The Hayburner’s Heaven Stable operates a different policy. There, it’s only groom to one horse and vice versa. For example, Buffy and only Buffy looks after Foxchaser. She doesn’t look after any other horse. Melanie takes care of Gorgon. BigAlex looks after Bucephalos.

Groom => Horse

Horse => Groom

4. The exculsive Pamper-Your-Pet has the highest fees, and provides a luxury service for your horse. Here, each horse has several grooms assigned to it, and each groom is responsible for just one horse. For example, Patty, Vicky and Gina look after Oateater, Mandy, Pippa and Alyce look after Man O’War.

Horse =>> Groom

Groom => Horse

Gemma is right to make the primary key the student number, subject and date.

If the primary key were to be the student number only, it would cause errors as then if there were to be multiple entries for grades of the same student number, on the same date and same subject. It would mean that the student took multiple papers for one or many subject on the same day.

If the primary key were to be the student number and the subject, it would too cause errors as multiple entries could be entered for the same student number, for the same subject on the same date. So, it would mean that the student would be taking multiple papers for the same subject on the same day.

If the primary key were to be the student number, subject, date and grade, then it would mean that there can only be one grade for each student number. So it would mean that there would only be 101 values for the grade section from 0-100. So no student would actually get the same grade.

Draw up an E/R diagram for this situation. Your E/R diagram should follow the same

model as the E/R diagram for the Mondial database, which you have already

downloaded, except that it should show ‘cardinality constraints’. (It need not show

‘participation constraints’, i.e. whether participation in a relationship is mandatory.) For

this diagram, consider Students, Courses, Teachers, and Rooms to be Entity Types. Just

show the relationships that are mentioned here with example data. (For instance, show

the teacher in-charge-of course relationship, but not any other relationship that might

exist, such as teacher teaches-on course relationship.) All other data (BirthDates,

names, phone-extensions) may be treated as attributes of entity types. Note that we

have one compound attribute (Address) and one multi-valued attribute

(Phone-extension) and your diagram should reflect this.

(a) Look up information about the MUMPS programming language and the

database system which is part of it, and write a brief (half page) description of

them. Name two major industries which are users of MUMPS databases.

Two major industries using MUMPS databases are the health industry and the banking industry.

1. M.Ursu, 1999. Database system. Goldsmiths University of London

2. Data Entry Clerk

Available: en.wikipedia.org/wiki/Data_entry_clerk

(Accessed on 10 December 2012)

3. Data entry is a top cause of medication errors

CIS 209: Database Systems Page 32