Difference between Full backup and Copy-only full backup
How SQL Server Central thread does a full backup truncate the log? that full backup does not truncate the log:
No. Neither Full or Differential backups truncate the transaction log. - Lynn Pettis
No - a full backup does not truncate the log. - Chad Crawford
So what is the difference between SQL server copy only backup?
For the log backup, there is a copy-only backup which prevents the log chain from breaking without truncating the log. So what is copy-only full backup?
A copy-only backup is a special type of full backup, which is independent of the conventional sequence of backups. The difference between copy-only and a full backup is that a copy-only backup doesn't become a base for the next differential backup. A full backup works on all database recovery models.
At the very least you need to consider differential backups. Unless copy-only on the full is used, your next diff backup will be off. Copy-Only Backups:
Copy-only full backups (all recovery models) A copy-only backup cannot serve as a differential base or differential backup and does not affect the differential base.
The only difference between full and full-copy is that full-copy does not break the differential chain. Neither of them breaks the log chain nor truncates the log file.
Answer (1)
In the context of database backups, particularly with SQL Server, there are distinct differences between a full backup and a copy-only full backup. Both are crucial for database maintenance and disaster recovery, but they serve different purposes and have different impacts on the backup and restore process.
Full Backup
Definition: A full backup captures the entire database, including all its data, system tables, and transaction logs.
Impact on Backup Chain: A full backup resets the differential base, which means that any subsequent differential backups will be based on this full backup. Differential backups only include changes made since the last full backup.
Purpose: Full backups are typically part of a regular backup strategy. They serve as a primary recovery point and are often scheduled to occur at regular intervals (e.g., daily, weekly).
Restoration: To restore to a point in time using a full backup, you might need the latest full backup and subsequent transaction log backups.
Copy-Only Full Backup
Definition: A copy-only full backup is a special type of full backup that captures the entire database just like a regular full backup but does not affect the backup chain.
Impact on Backup Chain: A copy-only full backup does not reset the differential base. Subsequent differential backups will still be based on the last regular full backup, not the copy-only backup.
Purpose: Copy-only backups are used for special situations where you need to take a full backup without disrupting the existing backup strategy. This is useful for creating ad-hoc backups, such as before major changes or for archival purposes.
Restoration: While a copy-only backup can be used to restore the database, it does not interfere with the scheduled backup and restore procedures. It's as if the copy-only backup was never taken in terms of differential and log backups.
Key Differences
Differential Base Impact:
- Full Backup: Resets the differential base.
- Copy-Only Full Backup: Does not reset the differential base.
Backup Strategy:
- Full Backup: Integral part of the regular backup strategy.
- Copy-Only Full Backup: Used for special or ad-hoc backup requirements without altering the regular backup strategy.