Database Design Flashcards
Database Development Life Cycle (DDLC)
Subset of the software development cycle (within IS) dedicated to database
3 Main aspects of Information System
Static, Dynamic and Functional
3 Phases of Data Design Method
conceptual design
logical design
physical design
4 types of requirements needed for DBMS
information requirements (data characteristics)
Process requirements (data operations)
Dynamics requirements (evolution)
Integrity constraint requirements
3 Main activities in requirements gathering and analysis
- Glossary of terms
- Eliminate ambiguities (synonyms)
- Group homogeneous requirements
Contrary to belief, this phase is often the most difficult
Requirements gathering and analysis
difficult to standardize process of discovering what users actually want
Excercise 1 requirements examples
data - car has color
operational - must be inspected evey 2 years
dynamical - tariff llist updated each year
constraint - car can only belong to one category
Conceptual schema
result of conceptual design phase. formalized and integrated description of business needs
expressed independently of the DBMS adopted
Conceptual model
Adopted from conceptual schema, provides high-level descriptions independent of implementation
also independent of type of DBMS (relational, hierarchical, key-value)
Example of a conceptual design
E/R Schema
What two things should we take into accout during the logical design phase
integrity and consistency (constraints)
efficiency
two subphases of logical design phase
- restructuring of the conceptual schema
- Translation to logical model
Physical design phase
choices made strictly dependent on specific DBMS used
Application design
Creation of software modules for functions and user interface
