Database Design Tools

CASE (computer-aided-software-engineering) tools are software packages used to design and implement an information system.
(Databases, of course, are at the center of an information system.) There are many CASE tools available on the market, ranging from easy-to-use (intuitive) to extremely sophisticated (and not at all user-friendly).
Database designers find the drawing capabilities of CASE tools especially useful for creating database diagrams. The most common diagrams are:

1. Data flow diagrams, which display how data travel through an organization.
2. Entity-relationship (ER) diagrams, which illustrate business objects^[1], their characteristics, and how these objects relate to each other.

Some advanced CASE tools are capable of translating ER diagrams directly into SQL statements. Others are used to help design the user applications that interact with databases.
A CASE tool can not design a database.
Only a database designer can examine a database environment and decide which business objects and business rules ought to be represented in a database.

What purpose do business rules serve within the context of database design? Business rules play an indispensable role in the context of database design, as they are essential in ensuring the consistency, integrity, and quality of the data stored within the database. These rules define the standards and constraints that govern the way data is entered, stored, manipulated, and retrieved within a database system. This descriptive overview highlights the key purposes that business rules serve in the context of database design and their significance in managing data effectively.

1. Ensuring Data Integrity: A primary purpose of business rules in database design is to ensure data integrity, which refers to the accuracy, consistency, and reliability of the data stored within the database. By enforcing specific constraints and validation checks, business rules prevent the entry of erroneous, inconsistent, or duplicate data, thereby maintaining the integrity of the database. Examples of such constraints include unique constraints, which prevent duplicate entries, and referential integrity constraints, which maintain the consistency of relationships between entities in the database.
2. Representing Real-World Semantics: Business rules serve to represent the real-world semantics of the data and the relationships among the various entities in the database. These rules reflect the organization's understanding of its domain and provide a clear and accurate representation of the business logic. By incorporating business rules into the database design, the database can effectively model the reality of the organization's operations, enabling users to make informed decisions based on accurate and meaningful data.
3. Facilitating Data Consistency: Another essential purpose of business rules in database design is to facilitate data consistency across different applications and users within the organization. By establishing a set of standardized rules that govern the way data is managed within the database, business rules ensure that data remains consistent, regardless of the application or user accessing it. This consistency contributes to the overall reliability and usability of the database system.
4. Enhancing System Maintainability: Business rules contribute to the maintainability of a database system by serving as a central repository of the logic and rules that govern the data. This centralization makes it easier to update and modify the rules as business requirements evolve, ensuring that the database remains aligned with the organization's changing needs. Moreover, by encapsulating the business logic within the database itself, business rules reduce the complexity of application code, making it easier to maintain and troubleshoot.
5. Enabling Compliance and Auditing: In many industries, organizations are subject to regulatory compliance requirements that dictate specific rules for data management. Business rules play a crucial role in enforcing these requirements within the context of database design, ensuring that the organization adheres to the necessary regulations. Additionally, the implementation of business rules within the database can assist with auditing processes, as the rules provide a clear and traceable record of the constraints and validations applied to the data.

Business rules serve a vital purpose in the context of database design, as they contribute to ensuring data integrity, representing real-world semantics, facilitating data consistency, enhancing system maintainability, and enabling compliance and auditing. By incorporating business rules into the design process, organizations can create a robust and reliable database system that effectively represents their business domain and meets their data management needs.
A set of rules or conditions describing the business polices that apply to the data stored on a company databases.
The next lesson concludes this module.

CASE (Computer-Aided Software Engineering) packages are software packages which include tools to help with database design. The main goal of these packages is to give database designers a way of representing systems that are too complex to understand in their source code or schema^[1] based forms. They help automate software development and maintenance tasks and usually contain tools for system analysis, project management, and design.

CASE tools can serve many functions in database design, including:

1. Collecting and analyzing data
2. Designing a data model
3. Feasibility analysis
4. Requirements definition
5. Implementing the database
6. Prototyping
7. Data conversion
8. Generating application code
9. Generating reports
10. Programming and testing
11. Maintenance

CASE tools can provide many advantages when used in database design, including:

1. Improved productivity in development
2. Improved quality through automated checking
3. Automatic preparation and update of documentation
4. Encouragement of prototyping and incremental development
5. Automatic preparation of program code from requirements definition
6. Reduced maintenance systems

However, there are also some disadvantages to using the tools in database design, including:

1. Cost increase
2. Need for specialized training
3. Limitations in flexibility of documentation
4. Inadequate standardization
5. Slow implementation
6. Unrealistic expectations

[1]Business objects: Items in a business environment that are related, and about which data need to be stored (e.g., customers, products, orders, etc.)

[2]schema: A data view which is specified in a language which the DBMS software is designed to understand is called a schema.