Part 1 – Compare and contrast the relational model with other common
database management systems
Write a short essay (circa 750 words) which outlines the key elements of
both the relational and other database approaches, and provides a brief
comparison of the different approaches to databases management in GIS.
Part 2 – Design, implementation and interrogation of a non-spatial
database
A Manchester-based Housing Association has asked you to develop a
database to help it keep track of the maintenance of its property portfolio.
You have conducted your preliminary investigations and come to the
following initial conclusions:
For each site, the department needs to record the following details:
• the name of the site
• the area of the site
• the number of dwellings to be built on the site
The system will need to be able to record how many dwellings of each type
are being built on each site by each Sub-Contractor (i.e. How many
apartments are being built by French in Longsight?)
Each site is allocated to a single Development Control (DC) officer, but each
DC officer can look after more than one site.
Each DC officer has been issued with a mobile phone number, which the
system must record. Development Control officers are based in one of three
Areas (East, South, and West). The system must record the address and
telephone number of each office.
Each Sub-Contractor has a senior site architect based at their regional office
who acts as the Sub-Contractor’s liaison contact with the Housing
Association for all the sites in the region. The system must record:
• the postal address of each Sub-Contractor’s office
• the telephone number of the office
• the liaison contacts’ names and mobile phone numbers
Further ‘rules’ may occur to you as you study the datasheets in detail, and
imagine how the Housing Association would wish to process its data.
During your investigations, you found that the Chief Housing Officer is
presently attempting to keep track of residential developments using three
paper lists. Sample entries to the lists are given in Tables 1, 2 and 3 of the
appendix (see Moodle).
Although the Chief Housing Officer needs to be able to see details of all the
sites, the DC Officers in the Area Offices usually often only want to see
details of sites within their own areas.
Your task is to design, implement and document the required database.
You should submit:
1. A report that:
A. Describes the conceptual model, which you would produce as a
basis for the Development Sites database.
B. Documents your implementation of your design using PostgreSQL.
You should:
o Create the tables, indexes and constraints that your conceptual
design requires;
o Provide the SQL CREATE table statements you used to create
your database;
o Insert the sample values from the tables in the Appendix (see
Moodle) into corresponding tables and use ‘SQL SELECT * FROM’
commands to provide listings of your tables;
o Refer to the unit materials for some ideas about indexing and
choice of keys. Your aim is to implement a design in Third
Normal form.
C. Indicates the success of your database design by answering each of
the following questions:
I. Which types of properties, and how many of each type, are
being built on the Park Estate site?
II. Which builders are building Semi-detached houses in the East
area? (No builder should appear more than once).
III. Which builders are developing sites in the West Area (No
builders should appear more than once)?
IV. How many Semi-detached houses are being built in the South
Area?
V. What is the average size of site, and total number of hectares
of residential land being developed in each office Area (One
query)?
VI. The Chief Housing Officer wants a list of all current sites that
will show her the Sub-contractor(s) on each site, and the Subcontractors’ contact telephone number, along with the name
and telephone number of their architect. The list is to be in
alphabetical site order.
VII. Produce a list of the site names and site areas (ha) of sites that
are larger than or equal to the size of the Hill Lane site (one
query).
VIII. Create a ‘East_Sites’ view of the database that will show
details of the sites within the East Area.
2. A backup of your database.
Use the ‘back up’ facility in PostgreSQL Administrator program to create a
backup file of your database and submit it alongside your report in Moodle.
Your report should provide a sufficient explanation of your database but,
occasionally, it is necessary for the assessor to be able to refer directly to a
student’s database to work out what has happened.