sqlfriends (9/2/2015)
Just notice this, you said transaction backup is fully independent even not on full backup? (except that one case you mention).I thought we will always need a full first as the base for the restore., the transaction backup or differentical backup on top of it?
Thanks
But the logs are not tied to a particular full backup. Let's say you have a full backup every 12 hours. You also have log backups every 15 minutes. Now, let's say you want to restore to a point in time today at 3pm. We could use our original full backup from the day before and then 39 hours worth of logs. Or, we could use the noon full backup and then 3 hours worth of logs. The full backups and the log backups are not connected.
Let's say we also have differentials running in the six hours between the log backups. Each differential is connected directly to the last full backup. No choices, options. If we wanted to restore to 7am, we could use the midnight full and the 6am differential. We couldn't use the full from noon the previous day because there was another full taken between the two.
I hope that helps to clarify a little.
"The credit belongs to the man who is actually in the arena, whose face is marred by dust and sweat and blood"
- Theodore Roosevelt
Author of:
SQL Server Execution Plans
SQL Server Query Performance Tuning