c# library for qr code Backup mirroring in C#.NET

Create QR Code in C#.NET Backup mirroring

10.3.3 Backup mirroring
QR Code JIS X 0510 Encoder In Visual C#.NET
Using Barcode maker for .NET Control to generate, create QR image in Visual Studio .NET applications.
www.OnBarcode.com
Scan QR Code In C#
Using Barcode reader for .NET framework Control to read, scan read, scan image in .NET framework applications.
www.OnBarcode.com
There is no such thing as too many backups. One of the optional backup clauses is MIRROR TO. Here s an example:
UPC Code Maker In C#
Using Barcode drawer for Visual Studio .NET Control to generate, create GS1 - 12 image in .NET applications.
www.OnBarcode.com
Barcode Printer In Visual C#.NET
Using Barcode encoder for Visual Studio .NET Control to generate, create Barcode image in .NET framework applications.
www.OnBarcode.com
-- Mirror the backup to a separate backup server using a UNC path BACKUP DATABASE [AdventureWorks2008] TO DISK = N'G:\SQL Backup\AdventureWorks-20080701.bak' MIRROR TO DISK = '\\BACKUP-SERVER\SQL-Backups\AdventureWorks-20080701.bak' WITH FORMAT
Linear Barcode Generation In C#
Using Barcode maker for .NET framework Control to generate, create Linear Barcode image in .NET applications.
www.OnBarcode.com
Encode Code 128 Code Set B In C#
Using Barcode generation for .NET framework Control to generate, create ANSI/AIM Code 128 image in VS .NET applications.
www.OnBarcode.com
Enabled by default on compressed backups.
Barcode Printer In C#
Using Barcode generator for Visual Studio .NET Control to generate, create Barcode image in VS .NET applications.
www.OnBarcode.com
Identcode Maker In C#
Using Barcode printer for VS .NET Control to generate, create Identcode image in VS .NET applications.
www.OnBarcode.com
Backup options
Quick Response Code Encoder In None
Using Barcode generation for Software Control to generate, create QR Code image in Software applications.
www.OnBarcode.com
Draw QR In Java
Using Barcode drawer for BIRT reports Control to generate, create Quick Response Code image in BIRT applications.
www.OnBarcode.com
The MIRROR TO clause allows a backup to be streamed to multiple destinations. The typical use of this option is for making a duplicate backup on a file server using a Universal Naming Convention (UNC) path to a file share (in the previous example, \\BACKUP-SERVER\SQL-Backups). This option provides multiple advantages: Additional backups for protection against media failure. Different retention periods for different locations; for example, the file server backups can be retained for a longer period on disk when compared to the backup file on the database server. The tape archive process can archive from the file share rather than the database server. Not only does this reduce the additional load the tape archive process places on the database server, it also avoids the need for tape drivers and associated software to be installed on the database server. In concluding this section, let s take a look at the challenge of coordinating backups across multiple databases.
Decode Denso QR Bar Code In C#
Using Barcode scanner for Visual Studio .NET Control to read, scan read, scan image in Visual Studio .NET applications.
www.OnBarcode.com
Barcode Scanner In None
Using Barcode reader for Software Control to read, scan read, scan image in Software applications.
www.OnBarcode.com
10.3.4 Transaction log marks
Print Data Matrix In Java
Using Barcode encoder for Android Control to generate, create Data Matrix image in Android applications.
www.OnBarcode.com
Painting Barcode In None
Using Barcode generation for Microsoft Excel Control to generate, create Barcode image in Office Excel applications.
www.OnBarcode.com
A common backup requirement is for coordinated backups across multiple databases. This is usually a requirement for the restore process rather than the backup when a database is restored, all associated databases must be restored to exactly the same point. Synchronized restores are enabled using transaction log marks. Before we take a look at using them in a restore scenario, let s see how they re used in recovering from an unintended action. Consider the following statement, which increases product prices by 2 percent:
Scan Barcode In Java
Using Barcode decoder for Java Control to read, scan read, scan image in Java applications.
www.OnBarcode.com
Barcode Maker In .NET Framework
Using Barcode generation for .NET framework Control to generate, create Barcode image in Visual Studio .NET applications.
www.OnBarcode.com
-- Update all prices by 2% BEGIN TRANSACTION updatePrices WITH MARK 'Updating Prices Now'; UPDATE Products SET Price = Price * 1.02 COMMIT TRANSACTION updatePrices
QR Code 2d Barcode Printer In Java
Using Barcode generator for Java Control to generate, create QR Code ISO/IEC18004 image in Java applications.
www.OnBarcode.com
Make Barcode In Objective-C
Using Barcode generation for iPhone Control to generate, create Barcode image in iPhone applications.
www.OnBarcode.com
Let s imagine we only intended to update some products, not all of them, as shown in the previous statement. Short of running additional commands to roll back the price increase (and other flow-on effects), we d be looking at a database restore, but if we can t remember the time of the update, a transaction log recovery using the STOPAT option won t help. One of the optional clauses we used in the update price transaction was WITH MARK, and we can use that in a restore command. After performing a restore of a full backup in NORECOVERY mode, we can then restore a transaction log backup made after the transaction to the point immediately before the mark, using the STOPBEFOREMARK option:
USS Code 128 Generator In Objective-C
Using Barcode drawer for iPhone Control to generate, create Code 128 Code Set A image in iPhone applications.
www.OnBarcode.com
GS1 DataBar Encoder In .NET
Using Barcode drawer for .NET Control to generate, create DataBar image in .NET framework applications.
www.OnBarcode.com
-- After restoring the full backup, roll forward the transaction log -- Use the STOPBEFOREMARK option to stop before the marked transaction RESTORE LOG [AdventureWorks2008] FROM DISK = N'G:\SQL Backup\AdventureWorks-log.bak' WITH RECOVERY, STOPBEFOREMARK = 'updatePrices' GO
Backup and recovery
Now that s all well and good (and very handy), but how does that help us with coordinating backups and restores across multiple databases Well, by encapsulating statements that update multiple databases within a single marked transaction, we can achieve the desired result (see listing 10.2).
Listing 10.2 Marking multiple transaction logs for coordinated restores
-- Use a dummy transaction to mark multiple databases -- If required, each database can be restored to the same point in time BEGIN TRANSACTION backupMark WITH MARK UPDATE db1.dbo.dummytable set col1 = 1 UPDATE db2.dbo.dummytable set col1 = 1 -- other databases here ... COMMIT TRANSACTION backupMark
By executing a simple update statement in multiple databases within one transaction, we re marking the transaction log of each database at the same time. Such an update statement could be executed immediately before transaction log backups are performed, thus enabling the backups to be restored to the same point in time using the STOPBEFOREMARK that we saw earlier. Bear in mind, however, that data entered in the databases after this transaction will be lost, and this is an important consideration in a coordinated restore scenario. Using transaction marks to enable synchronized restores across multiple databases is one example of using backup/restore features beyond the basics. While a basic backup/restore approach may suffice for small databases, it s insufficient for very large databases (VLDBs). In the previous chapter, we covered the use of filegroups as a mechanism for enabling enhanced administration options. We also explored a best practice whereby user objects are placed on secondary filegroups so that the only objects in the primary filegroup are system objects. Let s take a look at that process in more detail, and see how it can be used to minimize the user impact of a restoration process.
Copyright © OnBarcode.com . All rights reserved.