Online Oracle Database Incremental Backups - VERITAS NetBackup White Paper

Figure 4: Online, high performance database backups enabled through multiplexing.
NetBackup also minimizes downtime by providing very fast recovery of databases, whole disks, or even entire sites in the
event of a disaster. NetBackup maximizes restore performance by recovering multiple data streams in parallel from a
multiplexed tape or across multiple tape drives, especially when used with fast tape technologies such as STK 9840, Magstar,
DLT, Mammoth, etc. On systems with a locally attached tape device, NetBackup optimizes throughput by utilizing shared
memory and other high performance data transfer techniques. Whatever the environment, NetBackup has the flexibility to
provide continuous availability of databases or application-specific data with only minimal impact on user response times.

Online Oracle Database Incremental Backups

Oracle backup and restore performance can be drastically increased by implementing the NetBackup for Oracle Advanced BLI
Agent. Online Oracle database block level incremental (BLI) backups back up only changed file system blocks, virtually
eliminating the backup window and significantly reducing the volume of data to be backed up and, more importantly,
restored. This allows more frequent backups and continuous data availability while providing dramatically improved backup
performance and significantly reducing CPU and network overhead during backups. The functionality brings compelling
benefits to large database environments because backups – both in data volume and time – now are only proportional to
the amount of changed data, not sheer database size.
Incremental database backups are supported for both Oracle 7 and Oracle 8 databases, including Oracle 8i Proxy Copy
integration, whereby NetBackup is given the file names to be backed up rather than the database data itself. NetBackup
utilizes functionality within the VERITAS File System that identifies the blocks of data that have changed. Database
incremental backups leverage an underlying VERITAS File System technology called Storage Checkpoint. Storage Checkpoint
identifies and maintains a list of changed file system blocks as data changes. (i.e., no pre-processing is needed to find
changed data blocks as is the case with Oracle 8 RMAN). Through a VERITAS File System API, NetBackup extracts only
changed data blocks and can take either differential or cumulative block level incremental backups.
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