What is a standby database?
A Standby Database is an exact copy of an operational database on a remote (or local*) server,
ready to be used for backup, replication,
analysis, shadow environment and reporting, to name a few applications.
A standby database is far superior to a normal backup as it is instantly available in the event of a disaster.
To restore a backup takes time, and during the restore time the system is not available. With a standby database there is nothing to restore in the event of a disaster as the standby database is always available. It is possible to switch applications over to the standby database in a matter of minutes to allow business continuity.
Overview of standby database:
- Exact copy of main database in a remote (or local*) location.
- Is held up to date by applying changes from main database.
- In the event of a disaster, standby database becomes active.
- Users (or applications) are transferred to standby database to continue operation.
Technical overview of standby database: (see picture below)
- Database updates are captured in redo logs.
- Updates in redo logs are not permanent. They get overwritten, as there is a set number of redo logs and they written to in a cyclic fashion (when the last one is full, the first one is used again).
- A copy is made of the redo log which is then called an archive log. This is a permanent copy.
- The archive log is transferred to the standby server.
- The transferred archive logs are applied to the standby database.
- Standby database is up to date with primary database.
Dbvisit- Standby Database Technology
Dbvisit is a cost-effective and proven software solution to completely automate the Oracle standby database solution and ensuring business continuity.
When disaster strikes and you lose your primary database, your business can continue to operate as you switch over to the standby database.
Dbvisit manages the process with these unique features:
- Supports Oracle versions 8 to 11g, both 32 bit and 64 bit.
- Compresses archive logs before replicating, saving bandwidth.
- Uses standard secure ssh (even in Windows) for log transportation.
- Automatically creates the standby database.
- Runs as stand-alone software outside the database, not impacting database performance.
- Uses checksum to ensure Oracle logs have transferred correctly.
- Automatically recovers from network outages.
- Automatic graceful switchover (also referred to as role reversal) which may be used for planned outages. The primary database transitions to a standby database and the standby database transitions to a primary database with no data loss. Graceful switchover works for Oracle 8i, 9i, 10g and 11g.
- Full Oracle RAC support. Dbvisit support Oracle Real Application Cluster.
- Automatic space management. Dbvisit will automatically add new datafiles and tablespaces to the standby database which have been added to the primary database.
- Multiple Standby Databases from the same primary database. For example one standby database can be used for DR and another standby can be used for running large reports without impacting the primary database.
- Automatic notification included. Notification thresholds can be set.
- Supports ASM and flash recovery area.
- Simple to install and configure. Dbvisit on Windows comes with a modern Windows installer. With Dbvisit, any Oracle DBA can have a fully automated process to keep the standby database up to date in less than 30 minutes.
- Fully automated management and monitoring of the Oracle archive logs on both the primary and standby server. If space becomes an issue, automatic notifications will be sent, and archive logs can be automatically removed if required.
- Free 30 day fully featured trial version.
Dbvisit is the complete Oracle disaster recovery software to allow business continuity in an emergency.
Because of the above features, Dbvisit is a popular alternative to Data Guard. With its unique features and benefits, Dbvisit is gaining customer's loyalty all over the globe.
For more information please visit Dbvisit.com.
*A standby database in the same location as the primary server should not be used for disaster recovery but for reporting, shadow environment or analysis purposes only.
Dbvisit is a registered trademark of Dbvisit Software Limited
Oracle is a registered trademark of Oracle Corporation