SQL database solutions are very robust and used widely in server applications of various sizes, but you still need to consider planning for SQL data recovery. SQL is essential to many corporate computer systems, but when it fails, it can mean a lot of stress for whoever has to put that system back together and get everything up and running again.
As with anything, backups and disaster data recovery strategies are essential to have. Failure to backup on a regular basis is going to cost you everything on the server. In some cases, if you fail to do proper backups, or any backups at all, you could end up losing your job. You don’t want that to happen and that is why proper SQL database backups need to happen. It will make the entire process of SQL data recovery that much easier for you.
How to plan for SQL data recovery
In order to do a proper SQL data recovery, in a situation where the server has failed, you need to restore a set of SQL server backups in a proper restore sequence. Thankfully, SQL Server Restore and Recovery supports restoring data from backups for an entire database, a data page or just a data file. If you have a database to recover, you do a complete database restore. If you have a file to recover, you do a file restore and if you have a data page to recover, you do a page restore.
The complete database restore is the basic SQL data recovery strategy. This can involve restoring and recovering the backup, or you may need to do a full backup, followed by a restore, and then recover a differential backup.
There are advantages to doing a file or page restore though. For one, you are restoring less data and that is going to greatly reduce the time that is required to copy and recover the information. In addition, some SQL Server solutions allow for other data in the database to remain online and accessible, while you restore specific files in the background.
SQL data recovery models
It is important to note that there are three different models related to restoring from the three different types, they are as follows:
- Database restore: with full recovery, this provides a complete recovery if the log is available. In a bulk-logged recovery, some data loss may occur and in a simple recovery, any data since the last full backup is going to be lost.
- File restore: The full recovery offers full support, the bulk-logged recovery mode is only available in some cases and the simple recovery model only offers read-only secondary files.
- Page restore: This is the same as the file restore, except there is no simple recovery model available.
To Perform a Restore Sequence
If you are going to be doing a SQL data recovery, you are probably going to be doing this at some point. The most common steps are:
- Start the sequence and restore one or more data backups, whether this is a database backup, file backup or a page backup. Alternatively, you can restore the latest differential backups that are actually based off the full backups.
- Roll the database forward by restoring the log backups in sequence. You should finish with the backup that contains the recovery point.
If for whatever reason you encounter a problem, you can quit and restart the whole restore sequence. This can happen if you restore too many log backups and miss the recovery point you wanted.
Planning a restore sequence is a good idea for SQL data recovery. To do this, create a tail-log backup of the database, determine the recovery point, the type of restore you want to perform and then identify the backups that you are going to require and where those backups are going to be stored.