subject: The Database Development Life Cycle [print this page] Software development procedure consists of the activities needed for building software systems, and integrating the techniques and practices needed to be accepted. It also includes the planning of projects, tracking development, and managing the complications of programming software.
This different database related activities can be grouped into below phases (more commonly known as DDLC - Database Development Life Cycle). The most important step n implementing a database system is to find out what is needed -- What type of a database is required for the business organization, daily volume of the data, how much data needs to be stored in the master files etc. In order to collect all this required information, a database analyst need to spend a lot of time within the business organization talking to people, end users and get acquainted with day-to-day process.
In this stage the database designers will make a decision on the database model that is perfectly suited for the organization's requirements. The database designers will study the documents prepared by the analysts in the requirements analysis stage and then start developing a system that fulfills the needs.
Once the data model is designed, tested and demonstrated, the next phase is to evaluate the diverse database management systems and choose the one that is perfectly suited for the requirements of the organization. In order to identify best performing database for the organization, end user should be involved in this phase.
Once the evaluation and selection phase is completed successfully, the next step n the database development life cycle is logical database design. The conceptual design is translated into internal model in the logical design phase. This includes the mapping of all objects i.e. tables design, indexes, views, transactions, access privileges etc.
Physical database design is the procedure of selecting and characterizing the data storage and data access of the database. The data storage depends on the type of devices supported by the hardware, the data access methods and the DBMS.
Physical design is mainly significant for older database models like hierarchical and network models. Physical design is very vital in database development life cycle and has great significance as a bad design can result in deprived performance.
In most databases a new database implementation needs the formation of special storage related constructs to house the end user tables. These constructs typically comprise storage group, table spaces, data files, tables etc.
Once the database has been created, the data must be loaded into the database. The data required to be converting and migrating to the new database, if the loaded data is currently stored n a different system or in a different format.
The next phase is testing and performance tuning, this phase starts soon the data is loaded into the database. In this phase, database is tested and fine-tuned for performance, integrity, access and security constraints. It is very important that the database administrators and application programmers work together during this phase, because testing and performance tuning happens in parallel.
Once the data is loaded into the database and it s fully tested, the database is than released into production.
In operation phase, the database is accessed by the end users and application programs. This stage includes adding of new data, modifying existing data and deletion of obsolete data. The database administrators perform the administrative tasks periodically such as performance tuning, expanding storage space, database backup etc. This is the crucial phase as it provides useful information and helps management to make a business decision, thus making the smooth and well-organized functioning of the organization.
Database maintenance phase is very important and it is one of the ongoing phases in DDLC. Factors such as new business needs, new information requirements, acquisition of new data etc will make it essential to formulate ongoing changes and improvements to the existing design. The major tasks in this phase include: database backup and recovery, performance tuning, design modifications, access management and audits, usage monitoring, hardware maintenance, upgradation etc.
