Backup schedule
Full database backups Saturday 10PM
Differential backups Monday, Tuesday, Thursday, Friday at 10PM
Log backups every hour (on the hour) from 9AM to 6PM
Failure Occurred at Thursday at 10:30AM
What restore process should be followed?
Question: If a failure occurs at Thursday at 10:30AM, what is the restore process that should be undertaken?
First, if you're still able to access at least a part of the database, you would want to take a backup of the tail of the transaction log and save that.
You would restore your full backup from Saturday at 10, with the NORECOVERY option.
You would then restore the most recent differential which based upon your schedule is Tuesday at 10 PM, with the NORECOVERY option.
You would then apply every transaction log from 10PM Tuesday (that first one may have you an error about it not being needed) up until 9 AM Thursday, each with the NORECOVERY option.
Now, if you don't have a tail log backup, you restore your last transaction log backup from 10AM Thursday WITH RECOVERY and you are done with recovery to 10AM and 30 minutes of data loss.
If you do have the tail log backup available, you restore that 10 AM Thursday transaction backup with NORECOVERY and then restore the tail log backup and you're back to the point of failure with no data loss.
An introduction article to discuss about the various Database states for troubleshooting or health check purposes. More articles will be available in this series to see how to troubleshoot each and every states described in this article.
Data compression is a feature offered by many modern databases like Db2, Oracle, MySQL, MariaDB and SQLServer. However, many companies do not use this feature in their database systems. Either they lack the knowledge of its existence in the applicat…