Lesson 2 Flashcards
What are the Database development activities during the systems development life cycle (SDLC)? (7)
- Project Identification and Selection
- Project Initiation and Planning
- Analysis
- Logical Design
- Physical Design
- Implementation
- Maintenance
- Analyze current data processing
- Analyze the general business functions and their databases needs.
- Justify the need for new data and databases in support of business
Enterprise Modeling
- Identify scope of database requirements for proposed information system
- Analyze overall data requirements for business function(s) supported by database.
- Develop preliminary conceptual data model, including entities and relationships
- Compare preliminary conceptual data model with enterprise data model
- Develop detailed conceptual data model, including entities, relationships, attributes and business rules
- Make conceptual data model consistent with other models of information system
- Populate repository with all conceptual database specification
Conceptual Data Modeling
- Analyze in detail the transactions, forms, displays, and inquiries (database views) required by the business function supported by the database
- Integrate database views into conceptual data model
- Identify data integrity and security requirements, and populate repository
Logical Database Design
- Define database to DBMS (often generated from repository)
- Decide on physical organization of data
- Design database processing programs
Physical Database Design and Definition
- Code and test database processing programs
- Complete database documents and training material
- Install database and covert data from prior systems
Database Implementation
- Analyze database and database applications to ensure that evolving information
requirements are met - Tune database for improved performance
- Fix errors in database and database applications and recover database when it is
contaminated
Database Maintenance
___________ govern creating, updating, and
removing data in an information process and storage system,
thus they be described along with the data to which they are
related.
Business Rules and Policies
(3) Job as a Database Analyst is to:
- Identify and understand those rules that govern data
- Represent those rules so that they can be unambiguously understood by information systems developers and users
- Implement those rules in the database technology
This is “a statement that defines or constraints some aspect of business. Int is intended to assert business structure or to control or influence the behavior of the business… rules prevent, cause or suggest things to happen”
Business rule
This is an example of a _______: “A student may register for a section of a course if he or she
has successfully completed the prerequisites for that course.”
Business rule
Characteristics of a good Business Rule (7)
- Declarative
- Precise
- Atomic
- Consistent
- Expressible
- Distinct
- Business-oriented
A business rule is statement policy, not how policy is enforced or conducted; the
rule does not describe a process or implementation, but rather describes what a
process validates.
Declarative
With the related organization, the rules must have only one interpretation among
all interested people, and its meaning must be clear.
Precise
A business rule marks one statement, not several; no part of the rule stand on its
own as a rule (that is, the rule in indivisible, yet sufficient)
Atomic
A business rule must be internally consistent (that is, not contain conflicting
statements) and must be consistent with (and not contradict other rules)
Consistent
A business rule must be able to be stated in natural language, but it will be stated
in a structured natural language so that there is no misinterpretation
Expressible
Business rules are not redundant, but a business rule may refer to other rules (
especially refer to definitions)
Distinct
A business rule is stated in terms business people can understand, and since it is
a statement of business policy, only business people can modify or invalidate a
rule; thus, a business rule is owned by the business
Business-oriented
Where do business rules appear?
- Description of Business Functions
- Events
- Policies
- Units
- Stakeholders and other objects
These are identified by asking questions about the who, what, when, why and how of the
organization.
Rules
____________ has to be persistent in clarifying initial statements of rules because initial
statements may be vague and imprecise.You should be prepared to ask such questions as:
* “Is this always true”
* “Are there special circumstances when an alternative occurs?”
* “Is there only one of those or are there many?”
Data Analyst
Data names should: (6)
- Relate to business, not technical
- Be meaningful
- Be unique
- Readable
- Composed of words taken from an approved list
- Repeatable
__________a high-level data model. It is based on a perception of a
real world that consists of a collection of basic objects, called entities, and relationships among
these objects.
Entity-Relationship Model
