What are Flat Files?
A flat file is a file that has no repeating groups. Figure H-1(a) shows a flat file, and Figure H-1(b) shows a
file that is not flat because of the repeating field Item. A flat file can be stored in any common file
There are two levels of Modeling to consider:
1) Modeling Requirements for the user
Semantic Object Diagrams
Prototypes (sample screens and reports)
2) Models that represent implementation strategies
MySQL Conceptual Architecture
Figure 2: General High Level RDBMS Logical Modules
2002, Bannon, Chin, Kassam, Roszko, MySQL conceptual architecture
Query Processing interacts with various applications and interfaces
(Administrative Utilities, Client Interf
DATA STRUCTURES for DATABASE
REVIEW: MEMORY BASICS
Random Access Memory (fast, volatile)
Processing is done in RAM. Data brought in from disk/stored back to disk.
mailboxes (different sizes/addresses) vs contents
variables refer to mailbox contents
Transformation of ER Models into Relational Designs
The quick and dirty executive overview
Before building a database, the ERD must be transformed into a
Relational Schema Diagram (RSD). The RSD represents the
database schema in a format appropriate for i
Power*Architect Data Modeling Tool
There are many tools available for designing databases using the Entity-Relationship Model.
Visio is available free from our MSDNAA license agreement. It has many uses beyond data
modeling. As youve noted in the text, Kr
Practice with Power Architect
An Entity Relationship Diagram (ERD), should not show attributes labeled as primary key
(PK) or foreign key (PK). Entity identifiers are shown in the top section of the entity rectangle.
Neither should an ERD show intersectio
ID-dependent entity: an entity whose identifier includes the identifier of another
entity (parent). The ID-dependent entity cannot exist unless its parent also exists.
See Figure below
The identifier of such an entity is a composite.
In the ER model, ID-d
An example of a flat file: A flat file is a file in which the records have no repeating groups.
Suppose this file needs to be processed in order by emplo
ITFN 2214 Midterm Study Guide
The Midterm will focus on material covered in the first half of the
semester Chapter 7
The test will contain one or more of the following sections: