Considerations for Backing Up and Restoring System Databases
Posted by belthazor78 su 30 ottobre 2011
Ecco finalmente un bel riquadro che racchiude tutti i database di sistema di un SQL Server, le modalità di recupero e per ultimo, ma di grande importanza, l’importanza che assume un backup per i database di sistema.
Ecco il link: http://msdn.microsoft.com/en-us/library/ms190190.aspx
Ed ecco lo schemino:
|System database||Description||Are backups required?||Recovery model||Comments|
|master||The database that records all of the system level information for a SQL Server system.||Yes||Simple||Back up masteras often as necessary to protect the data sufficiently for your business needs. We recommend a regular backup schedule, which you can supplement with an additional backup after a substantial update.For more information, see Considerations for Backing Up the master Database.|
|model||The template for all databases that are created on the instance of SQL Server.||Yes||User configurable1||Back up modelonly when necessary for your business needs; for example, immediately after customizing its database options.Best practice: We recommend that you create only full database backups of model, as required. Because modelis small and rarely changes, backing up the log is unnecessary.For more information, see Considerations for Backing Up the model and msdb Databases.|
|msdb||The database used by SQL Server Agent for scheduling alerts and jobs, and for recording operators. msdb also contains history tables such as the backup and restore history tables.||Yes||Simple (default)||Back up msdbwhenever it is updated.For more information, see Considerations for Backing Up the model and msdb Databases.|
|Resource (RDB)||A read-only database that contains copies of all system objects that ship with Microsoft SQL Server 2005 or later versions.||No||—||The Resource database resides in the mssqlsystemresource.mdf file, which contains only code. Therefore, SQL Server cannot back up the Resourcedatabase.
You can perform a file-based or a disk-based backup on the mssqlsystemresource.mdf file by treating the file as if it were a binary (.exe) file, instead of a database file. But you cannot use SQL Server restore on the backups. Restoring a backup copy of mssqlsystemresource.mdf can only be done manually, and you must be careful not to overwrite the current Resource database with an out-of-date or potentially insecure version.
|tempdb||A workspace for holding temporary or intermediate result sets. This database is re-created every time an instance of SQL Server is started. When the server instance is shut down, any data in tempdb is deleted permanently.||No||Simple||You cannot back up the tempdb system database.|
|Configuring Distribution||A database that exists only if the server is configured as a replication Distributor. This database stores metadata and history data for all types of replication, and transactions for transactional replication.||Yes||Simple||For information about when to back up the distribution database, see Backing Up and Restoring Replicated Databases.|