With e-commerce driving the design and demands of modern business applications, high performance and high availability database computing is now the service standard. This modern performance standard is associated with a high cost of downtime.
Administration techniques developed for this type environment demand negligible impact on the system while performing standard maintenance tasks. The ability to perform online data reorganization in these environments would greatly assist in maintaining the overall database availability, and potentially reduce or eliminate planned downtime. This, in turn would increase the application return on investment (ROI) and lower the total cost of ownership (TCO). Online reorganizations would also lend an administrator unprecedented flexibility to modify table physical attributes and transform both data and table structure with users having complete access to the database.
The standard method for reorganizing tables is to develop sophisticated O/S and database scripts to either automate reorganizations or squeeze them in during a scheduled maintenance downtime. While this is the common method, there are associated downtime, administrative, and development costs. Additionally, if this method of reorganization fails, it is a waiting game until the next opportunity arises.
Conventional wisdom dictates correct initial table sizing to prevent the need to reorganize, but even the most meticulously sized tables can require storage parameter modifications to make optimal use of space under evolving conditions.
Reasons to Reorganize Tables and their dependant objects are subject to reorganization in order to make the most efficient use of space, prevent performance issues, or conform to new hardware architecture.