IS 342 AMARAVADI
FIRST MIDTERM – OUTLINE OF TOPICS
Database Preliminaries (Database introduction)
- Data vs Information: concepts of entities, attributes, primary key, files, file processing problems, usage of data/information.
- Definition of DBMS vs database; file/table, records, fields, schema, primary and secondary keys.
- Operational and advanced uses of databases.
- Organizational importance of databases (engine for all IS applications, starting point in the transformation of data to information, decision support, strategic resource).
- Database objectives: to make data available, to ensure data quality and integrity, centralized control of data, data independence.
- DBMS activities: define schema/structure (data definition), enter data, modify data, query data (SQL), get reports – query-by example (QBE).
- The database development cycle (planning, requirements definition, logical and physical design, implementation, maintenance).
- The database concept/approach.
- Entities, entity classes and attributes.
- Ignore the student administration application.
Database Fundamentals (Database evolution and environment)
- Evolution of DBMS: intro of business computers, use in TP, problems, academic formulations, standardization of DBMS concepts.
- The file processing era and problems caused: uncontrolled redundancy, program-data dependence, program maintenance, poor data quality, inability to get reports, application backlog.
- The DBMS approach : conceptualization of data, organized design, centralized management, system controlled access, checks on data quality, query and reporting.
- Rules for getting information from multiple tables
- Database terminology: schema/structure/definition, file/table/relation, record, attribute/field.
- Database architecture: the three-schema architecture (external, conceptual and internal)
- Different classes of users in a DBMS (end users, administrators and developers).
- DBMS components: Data definition, SQL, Programming language interface, Data dictionary, Screen/Report generation, Application generation, Export/Import.
- Components of a database environment: Data dictionary, database client, SQL server, directory server Enterprise Applications programs, database.
Database Planning
- The database development cycle (planning, requirements definition, logical and physical design, implementation, maintenance).
- About database planning: areas of organization, database size, # of analysts, HW/SW requirements.
- Without adequate planning: org. changes impact development, schedule changes, rework, inaccurate estimation of resources (ignore).
- Notion of a business process: a group of related activities
- Functions, processes and activities
- Activity data relationship: process/activity can create/update/Delete data.
- The Enterprise Data Model (EDM): you need to be able to draw an EDM.
- Pre-requisites of planning: management commitment, project team.
- Planning metamodel: Study the organization from the top down, identify functions, processes and activities, identify which functions impact CSFs, study the applications and the eclasses they handle.
- Steps in planning : identify background, information used, develop planning matrices, Enterprise model, define scope of project; planning matrices (function vs CSF, process vs eclass, application vs eclass)
- Planning objectives: scope, overview of info requirements, critical processes & information classes, resource requirements.
- Elements of a database plan (ignore).
- Outcomes of planning: planning matrices, preliminary data model, team assignments, application requirements, project priorities.
- Planning pitfalls: insufficient management support, strategic plan not available, direction not known and lack of co-ordination.
Requirements Definition
- Information collected during RD: data structure and rule/constraint information.
- Constraints: Integrity constraints and performance constraints.
- Steps in RD (FYI): define scope, select methodology, identify user views, develop data model, cross-check, specify constraints.
- Top-down vs bottom-up approaches: Conceptual Data Model vs Enterprise Data Model;
- ER Model
- Basic modeling concepts: Entity classes, attributes (multi-valued, derived) and relationships (degree, cardinality, class/subclass, recursive).
- Basic symbols of ER: Entity class, relationship, primary-key, attribute, multi-valued attribute, Gerunds, relationships of different degrees (unary/recursive, binary, ternary), relationship cardinalities, class-subclass (sub-types, super-types), exclusive and exhaustive, non-exclusive and non-exhaustive; minimum-maximum cardinalities.
- ER drawing guidelines: identify eclasses, identify relationships among eclasses, use rectangles for eclasses and diamonds for relationships, depict the cardinalities, use ovals for attributes, label attributes, underline the pkey.
- ER additional guidelines : build model around central eclass, group attributes with entity classes, show only relevant attributes, do not show computed attributes or values, underline pkey, label all relationships, refine.
- User views: reports, receipts, forms, memos and screen displays.
- Constraints: domain, integrity, business and performance – you need to be able to define and give examples of each.
NOTE:
Please note that concepts and conventions are very very important. There will be a two point penalty for each violation of convention. Need to know conventions for Enterprise Data Model and ER Model.
SAMPLE TEST
SECTION I
This part will have twenty T/F, multiple choice, match the following type questions. Following are examples.
1. An SQL processor is a component of a DBMS.
True False
2. The file processing approach allowed querying of data.
True False
3. Cardinality refers to the number of entity classes involved in a relationship.
True False
4. The Data entry stage of DBMS development is concerned with creating the schema.
True False
5. The ER model is developed during _________ stage:
a. planning
b. requirements
c. design
d. implementation
SECTION II
This section will have ten short theory questions & problems, following are examples.
1. A car rental company rents cars to renters (who may be private parties or corporations). The company likes to keep track of the renter’s name, phone#, address and driver’s license#. The renter has to sign a rental agreement, which includes the name, address of renter, renter’s phone, start and end dates, type of vehicle rented, license plate# and rental rate. On the cars, the company tracks the license plate#, mileage, and date last serviced. Draw an ER model using correct notation.
2. What type of information is identified during requirements definition process?
3. Give two different examples of a domain constraint.
4. In a manufacturing situation, each assembly consists of a number of parts each with part#, cost, material and acceptable tolerance. The assembly itself has a name (unique), a description, instructions (one large text field) and the parts of which it is comprised. Draw an ER model.
SECTION III
This section will have only one big problem. Following are examples.
1. RECYCLED TRACTOR
Recycled tractor buys used and damaged tractors, refurbishes them and then resells them. Recycled Tractor obtains the tractors from repair shops, auctions, farmers who simply want to sell their old tractors, and a variety of other sources in the agricultural industry. The individuals who search for the used tractors are called trackers. When a lead on a potential tractor is obtained, the tracker calls up the individual who wants to sell the tractor and asks them questions about the tractor manufacturer, model and the year the tractor was built. Sometimes, a lead has tractors at more than one location. For example, a farmer might own two or three other farms and have a tractor for sale at each location. Two individuals, called evaluators, are assigned to examine each tractor on site i.e. if there are two tractors, then four evaluators would be needed. An evaluator goes to the address of the tractor, appraises its value and then calls in a bid on the tractor. After both bids have been received, the tracker makes a judgement on the value of the tractor, then contacts the lead and makes an offer to the owner of the tractor. If the tracker and the lead can agree on the price, the tracker purchases the tractor.
2. CONFERENCE SITUATION
A conference [e.g. International Conference on Information Systems, ICIS] has different tracks corresponding to the different areas of the field. For e.g. there can be an AI track, a DSS track, an OIS track etc. A track could in turn have one or more sessions. A session is a time period during which people who are interested in the track are treated to a presentation of research by different participants. Sessions have a session title [AI – Session 1] session chair, a start time, end time and a location. Both tracks and sessions have chairs [who are also researchers]. A participant [or participants] could present one or more papers in the conference. A paper could be presented by more than one researcher. A paper has a title, author(s) and affiliation [university or company] and discussant. A participant can present only once in each track/session. Typically, each presentation will be critiqued by a discussant. A conference has many participants. Each participant/researcher represents a University/Company. Participants could simply be attendees who sit and listen to presentations made by other participants; and/or they could participate as presenters [people who present papers]; and/or discussants [people who discuss presentations made by other researchers] or could serve on the executive committee, the committee that plans and organizes the conference. Assume that discussants, session and track chairs are also part of the executive committee.