Oracle Database 11 g - Online Public Access Catalog

310 CHAPTER 6 ■ BACKUP AND RECOVERYResynchronizing the Recovery CatalogYou can resynchronize the RMAN recovery catalog from a remote database using an enhancedreysnc catalog command, which does the resynchronization when you add the new db_unique_name option.Before you use the resync catalog command to perform the recovery catalog resynchronization,however, you must first define the connect identifiers for the standby databases inyour Data Guard configuration by using the configure command with the new clause connectidentifier.Here’s how you define a connect identifier for a specific standby site in your Data Guardconfiguration:RMAN> configure db_unique_name 2> connect identifier ;You must enclose the connect identifier name you supply in quotes. The database you areconnected to through RMAN will connect automatically to the remote standby site using theconnect identifier you create, as the privileged user sys.Although RMAN can use the connect identifier to process information back and forth withthe remote standby site, in this chapter, our interest is in using the connect identifier as part ofthe resync catalog command. You can use the resync catalog command to resynchronize thecatalog with a specific standby site’s information (by using the site_name clause), or if you haveconfigured connect identifiers for all databases in your Data Guard configuration, use the allclause in the resync catalog command. Here’s an example:RMAN> resync catalog2> from db_unique_name all;Oracle recommends you define the connect identifier for all databases in your Data Guardconfiguration.Backup File Accessibility GroupsIn Oracle Database 11g, all backup, restore, and recover commands automatically figure outthe correct file names for each of the standby sites in the Data Guard configuration. This transparencyis extremely useful when you’re dealing with databases that contain a large number ofdatafiles or use an automatic storage management (ASM) file system or an Oracle ManagedFiles (OMF) file system, where the file names tend to be unwieldy.You can create a group of sites that can share backups for a device type by using the newconfigure group command to create a group of standby sites, formally known as a backup fileaccessibility group. A standby site can belong to multiple groups. Here’s how you create a newgroup of standby sites:RMAN> configure group 2> for device type disk3> site_nameA, site_nameB, site_nameC;Make sure you connect to the recovery catalog before executing the command shownhere. The target database you’re connected to can be mounted or open. The previous commandcreates a backup file accessibility group with three standby sites, whose backups are accessible