The "Post Design Stages" of the database life cycle refer to the stages that occur after the database has been designed and implemented. These stages are focused on maintaining and improving the database over time. The post design stages typically include:
Testing and Validation: Once the database has been designed and implemented, it is important to test and validate the database to ensure that it functions as intended. This involves running test cases and validating the data and functionality of the database.
Implementation and Deployment: After the database has been tested and validated, it can be deployed in a production environment. This involves setting up the necessary infrastructure, such as servers and networks, and migrating the data from the old system to the new system.
Maintenance: Once the database is deployed, it requires ongoing maintenance to ensure that it continues to function properly. This includes performing regular backups, monitoring the system for errors or performance issues, and applying updates and patches as needed.
Performance Tuning: Over time, the database may experience performance issues due to increased data volume or changes in usage patterns. Performance tuning involves identifying and resolving performance issues to ensure that the database remains responsive and efficient.
Security and Access Control: Security and access control are important considerations for any database system. Post-design stages involve implementing and maintaining appropriate security measures, such as access controls and encryption, to protect the data from unauthorized access and breaches.
Retirement and Archiving: At some point, the database may become obsolete or no longer needed. Retirement and archiving involve safely removing the database from production systems and preserving the data for archival or historical purposes.
The post design stages of the database life cycle are critical for ensuring that the database continues to meet the needs of the organization over time. By following best practices for testing, deployment, maintenance, performance tuning, security, and retirement, organizations can ensure that their databases remain secure, reliable, and effective.
The final two stages in the DBLC,
Monitoring, Modification, and Maintenance,
occur after the database design is complete.
The following paragraphs discuss these stages in detail.
Fourth Stage - Implementation
During the implementation stage of the DBLC, the tables developed in the ER diagram (and subsequently normalized) are converted into SQL statements. These SQL statements are then executed in the RDBMS to create a database.
By this stage in the database life cycle, the System Administrator has installed and configured an RDBMS.
In this case the System administrator is the person responsible for administering a multi-user computer system. His duties range from setting up and configuring system components (i.e. an RDBMS) to performing maintenance procedures (for example, database backups) on the system.
Certain database design books consider converting an ER diagram into SQL statements to be the final task in the logical-design stage. According to such books, implementation is just a matter of feeding SQL statements into an RDBMS and populating the database with data. The difference is not especially important.
Fifth Stage: Monitoring, Modification, and Maintenance
A successfully implemented database must be carefully monitored to ensure that it is functioning properly and that it is secure from unauthorized access. The RDBMS usually provides utilities to help monitor database functionality and security.
Database modification involves adding and deleting records, importing data from other systems (as needed), and creating additional tables, user views, and other objects and tools.
As an organization grows, its information system must grow to remain useful.
A well-designed database enhances the organization's ability to expand its information system
and has several key characteristics that contribute to its effectiveness and efficiency. These characteristics include:
Data Integrity: A well-designed database ensures that the data stored within it is accurate, consistent, and reliable. This is achieved through the use of data validation rules, referential integrity constraints, and other mechanisms to ensure that data is entered correctly and remains consistent over time.
Scalability: A well-designed database is able to handle increasing amounts of data and users without compromising its performance or availability. This is achieved through careful consideration of database architecture and optimization techniques, such as indexing, partitioning, and clustering.
Performance: A well-designed database is optimized for performance, ensuring that queries and transactions are executed quickly and efficiently. This is achieved through the use of proper indexing, normalization, and query optimization techniques.
Security: A well-designed database is secure, protecting data from unauthorized access, modification, or deletion. This is achieved through the use of access control mechanisms, encryption, and other security features.
Flexibility: A well-designed database is flexible, allowing for easy modification and adaptation to changing business requirements. This is achieved through the use of modular database design, which allows for the addition or removal of tables, fields, or relationships as needed.
Usability: A well-designed database is easy to use, with a clear and intuitive interface that allows users to quickly and efficiently access the data they need. This is achieved through the use of user-friendly interfaces, logical organization of data, and appropriate use of data visualization and reporting tools.
A well-designed database is characterized by its ability to effectively and efficiently store, retrieve, and manipulate data, while ensuring the integrity, scalability, performance, security, flexibility, and usability of the system.
Ongoing maintenance procedures include periodic database backups, for example, an important and ongoing maintenance procedure.
Again, the RDBMS provides utilities to assist in this task. The next lesson introduces a special class of tools often used in database design.
information system: Interrelated components (i.e., people, hardware, software, databases, telecommunications, policies, and procedures) that input, process, output, and store data to provide an organization with useful information.