No full database backup specified message

Category: Troubleshooting & error messages
Date: 16 Apr 2009
Product: SQL Log Rescue
Versions: 1.x

After selecting a database to analyze and a full backup to use, Log Rescue may show this message:

No full database backup specified. SQL Log Rescue may not be able to fully recover all data.

This situation can occur if the log is truncated or if there had been no transactions since the specified full backup. Log Rescue will attempt to recover transactions even if the log was truncated, however not all transactions may be returned if the log file had been subsequently shrunk because the data is no longer available in the log at that point.

For example, you may see the following behavior:

BACKUP DATABASE [Northwind] TO DISK='c:\backups\northwind.bak'
-- Update the Customers table in Northwind and run Log Rescue, choosing the backup you had just done: you will see your updates in the results

BACKUP DATABASE [Northwind] TO DISK='c:\backups\northwind2.bak'
-- Run log rescue. Choosing the first backup will work normally. Choosing the second backup will cause the error message

BACKUP log [Northwind] with truncate_only
-- Run Log Rescue. Choose either backup or both. The error message appears.

USE Northwind
DBCC SHRINKFILE(Northwind_log, 2)
-- Run Log Rescue. The error message will appear and transactions may be absent from the results.