Archive Database Access

Archive database access allows a database administrator to validate or selectively recover data from a database dump (an “archive”) by making the dump appear as if it were a traditional read-only database; this type of database is called an “archive database.”

Unlike a traditional database, an archive database uses the actual database dump as its main disk storage device, with a minimum amount of traditional storage to represent new or modified pages that result from the recovery of the database dump. A database dump already contains the images of many (or even most) of the database pages, therefore, an archive database can be loaded without having to use Backup Server to transfer pages from the archive to traditional database storage. Consequently, the load is significantly faster than a traditional database.

Archive database access lets you perform a variety of operations directly on a database dump.

The amount of storage needed for a traditional database load must be equal to or greater than the size of the source database; the loading of the database dump using Backup Server involves copying pages from the database dump into the storage that has been set aside for the traditional database.

By contrast, you can create an archive database using a minimal amount of traditional disk storage. When you load an archive database, the pages residing in the database dump are not copied by the Backup Server. Instead, SAP ASE creates a map that represents a “logical-to-virtual” mapping of the pages within the archive. This significantly decreases the amount of time required to view the data in a database dump, and reduces the storage requirement for loading the dump.

An archive database does not have to be a complete copy of the original database. Depending on the optimization used when dumping the database using sp_dumpoptimize, an archive database may be fully populated (every page in the database is in the database dump), or partially populated (only allocated pages are stored in the database dump).

Because the database dump is presented as a read-only database, a database administrator can query it using familiar tools and techniques such as:

In addition, transaction logs can be loaded into an archive database, thereby providing the assurance that the same load sequence can be applied when performing a restore operation. The figure below represents the differences between an archive database and a traditional database structure.

Image shows the components of a traditional database and a database with archive. The Archive database has all the same components (logical database pages, MAP, and a disk storage), but it also includes a database dump component.