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sys.fn_hadr_backup_is_preferred_replica (Transact-SQL)

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Used to determine if the current replica is the preferred backup replica.

Topic link icon Transact-SQL Syntax Conventions

Syntax

sys.fn_hadr_backup_is_preferred_replica ( 'dbname' )

Arguments

  • 'dbname'
    Is the name of the database to be backed up. dbname is type sysname.

Returns

Returns 1 if the database on the current instance is on the preferred replica. Otherwise returns 0.

Remarks

Use this function in a backup script to determine if the current database is on the replica that is preferred for backups. You can run a script on every availability replica. Each of these jobs looks at the same data to determine which job should run, so only one of the scheduled jobs actually proceeds to the backup stage. Sample code could be similar to the following.

If sys.fn_hadr_backup_is_preferred_replica( @dbname ) <> 1 
BEGIN
-- If this is not the preferred replica, exit (probably without error).
END
-- If this is the preferred replica, continue to do the backup.

Examples

A. Using sys.fn_hadr_backup_is_preferred_replica

The following example returns 1 if the current database is the preferred backup replica.

SELECT sys.fn_hadr_backup_is_preferred_replica ('TestDB');
GO

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See Also

Reference

CREATE AVAILABILITY GROUP (Transact-SQL)

ALTER AVAILABILITY GROUP (Transact-SQL)

Concepts

AlwaysOn Availability Groups (SQL Server)

Active Secondaries: Backup on Secondary Replicas (AlwaysOn Availability Groups)

Other Resources

AlwaysOn Availability Groups Catalog Views (Transact-SQL)