Tuesday, 7 February 2012

Automating Transaction Log Backups for All SQL Server Databases

Problem
Maintenance plans are a great thing, but sometimes the end results are not what you expect.  The whole idea behind maintenance plans is to simplify repetitive maintenance tasks without you having to write any additional code.  For the most part maintenance plans work without a problem, but every once in awhile things do not go as planned. Two of the biggest uses of maintenance plans are issuing full backups and transaction log backups.  What other approaches are there to issue transaction log backups for all databases without using a maintenance plan? 
Solution
With the use of T-SQL you can generate your transaction log backups and with the use of cursors you can cursor through all of your databases to back them up one by one. With the use of the DATABASEPROPERTYEX function we can also just address databases that are either in the FULL or BULK_LOGGED recovery model since you can not issue transaction log backups against databases in the SIMPLE recovery mode.
Here is the script that will allow you to backup the transaction log for each database within your instance of SQL Server that is either in the FULL or BULK_LOGGED recovery model.
You will need to change the @path to the appropriate backup directory and each backup file will take on the name of "DBname_YYYDDMM_HHMMSS.TRN".
DECLARE @name VARCHAR(50-- database name   DECLARE @path VARCHAR(256-- path for backup files   DECLARE @fileName VARCHAR(256-- filename for backup   DECLARE @fileDate VARCHAR(20-- used for file name 
SET @path 'C:\Backup\'  
SELECT @fileDate CONVERT(VARCHAR(20),GETDATE(),112
   + 
'_' 
   
REPLACE(CONVERT(VARCHAR(20),GETDATE(),108),':','')
DECLARE db_cursor CURSOR FOR  
SELECT 
name  FROM master.dbo.sysdatabases  WHERE name NOT IN ('master','model','msdb','tempdb'
   AND 
DATABASEPROPERTYEX(name'Recovery'IN ('FULL','BULK_LOGGED')
OPEN db_cursor    FETCH NEXT FROM db_cursor INTO @name   
WHILE @@FETCH_STATUS 0    BEGIN   
       SET 
@fileName @path @name '_' @fileDate '.TRN'  
       
BACKUP LOG @name TO DISK = @fileName  

       
FETCH NEXT FROM db_cursor INTO @name    END   

CLOSE 
db_cursor    DEALLOCATE db_cursor 
In this script we are bypassing the system databases, but these could easily be included as well. You could also change this into a stored procedure and pass in a database name or if left NULL it backups all databases. Any way you choose to use it, this script gives you the starting point to simply backup all of your databases.
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