By Sonia R. Lelii
StorageTek recently jumped into the database archiving market with its Life-Cycle Director software for IBM's DB2 database. LifeCycle Director is designed specifically for mainframe environments and archives inactive data onto cheaper media without impacting applications or the relational connections between tables and indexes in a database.
While the per-megabyte cost of disk is getting cheaper, price erosion pales in comparison to the rate of database capacity growth.
"The net effect is that you're paying for storage, and that's compounded when you factor in the cost of managing disks," says Ted Battreall, database archiving product marketing manager at StorageTek.
LifeCycle Director includes an automated policy capability. For example, an IT manager at a retail store can set a policy for the software to regularly scan the database to archive data on any customer that has not made a purchase at the store for, say, two years. That data is automatically moved from high-performance, high-cost disk arrays to either low-cost ATA or Serial ATA disk or tape. A pointer replaces the data that was moved so the application is unaware of the change. One of the primary issues with relational databases is the ability to archive data without interfering with the relationships between tables and indexes.
"It's all interconnected, and if you move a piece of data you still have to maintain the relationships," says Dianne McAdam, a senior analyst at the Data Mobility Group consulting firm. "You don't want the movement of data to impact the application. It should happen transparently."
Without automated, policy-based archiving software, administrators have to go through a more manual process for database archiving. According to StorageTek's Battreall, there are two methods database administrators can use. One method involves using a browser utility that runs against the database to gather data designated for archiving, but that approach involves creating a new, separate database for the data that is being archived. Another option involves changing applications code.
The pointer technology in LifeCycle Director is a key feature. "With pointers, you don't have to modify the application," Battreall explains.
The other side of the database archiving equation is retrieving the data once it has been archived. LifeCycle Director intercepts requests from SQL (Structured Query Language), which is the way applications talk to DB2. The software works as a "middleman" in retrieving archived data from disk or tape once an application makes a request.
According to Battreall, StorageTek made a move into this market because there is a technology gap in database archiving for mainframes.
Vendors such as OuterBay and Princeton Softech specialize in database archiving for the open systems market. (In fact, StorageTek uses Princeton Softech's database archiving software for open systems solutions.)