Developing a Backup and Recovery Plan

Having a well-documented backup and recovery plan is crucial for any SAP ASE site.

• Tracking Database Changes
  SAP ASE uses transactions to keep track of all database changes. Transactions are SAP ASE units of work. A transaction consists of one or more Transact-SQL statements that succeed—or fail—as a unit.
• Checkpoints: Synchronizing a Database and Its Log
  A checkpoint writes all dirty pages—pages that have been modified in memory, but not on disk, since the last checkpoint—to the database device.
• Automatic Recovery After a System Failure or Shutdown
  Each time you restart SAP ASE—for example, after a power failure, an operating system failure, or the use of the shutdown command—it automatically performs a set of recovery procedures on each database.
• Fast Recovery
  During a server restart after a planned or unplanned shutdown, or during high availability failover, a significant portion of time is spent on database recovery. Faster recovery minimizes database downtime.
• The sybdumptran Utility
  Use the sybdumptran utility to dump the most recent transactions when, due to the server suffering a catastrophic failure, you cannot use dump tran with no_truncate.
• Fault Isolation During Recovery
  The recovery procedures, known simply as “recovery,” rebuild the server’s databases from the transaction logs.
• Using the dump and load Commands
  In case of media failure, such as a disk crash, you can restore your databases if—and only if—you have regular backups of the databases and their transaction logs.
• Suspending and Resuming Updates to Databases
  quiesce database hold allows you to block updates to one or more databases while you perform a disk unmirroring or external copy of each database device.
• The mount and unmount Commands
  The mount and unmount commands make it easier to move or copy databases.
• Using Backup Server for Backup and Recovery
  Dumps and loads are performed by an Open Server program, Backup Server, running on the same machine as SAP ASE. You can perform backups over the network, using Backup Server on a remote computer and another on the local computer.
• Creating Logical Device Names for Local Dump Devices
  If you are dumping to or loading from local devices (that is, if you are not performing backups over a network to a remote Backup Server), you can specify dump devices either by providing their physical locations or by specifying their logical device names.
• Scheduling backups of user databases
  An important part of developing a backup plan is determining how often to back up your databases.
• Scheduling Backups of master
  Current backups of the master database are used to recover from failures that affect that database. If you do not have a current backup of master, you may have to reconstruct vital system tables while you are under pressure to get your databases up and running again.
• Scheduling Backups of the model Database
  Keep a current database dump of the model database.
• Schedule Backups of the sybsystemprocs Database
  The sybsystemprocs database stores only system procedures. Restore this database by running the installmaster script, unless you make changes to the database.
• Configuring SAP ASE for Simultaneous Loads
  SAP ASE can simultaneously perform multiple load and dump commands.
• Gather Backup Statistics
  Use dump database to make several practice backups of an actual user database and dump transaction to back up a transaction log. Recover the database with load database and apply successive transaction log dumps with load transaction.