Avaya 38HBK00001SCM Manual Do Utilizador

Restoring a database backup returns the database to the same state it was in when
the backup was created.  When restoring a database, SQL Server re-creates the
database and all of its associated files automatically by performing these steps:
1. All of the data from the backup is copied into the database; the rest of the

database is created as empty space.

2. Any incomplete transactions in the database backup, (transactions that were not

complete when the backup operation completed originally), are rolled back
(undone) to ensure the database remains consistent.

This process ensures that the restored database is a copy of the database as it
existed when the backup operation completed, except that all incomplete
transactions have been rolled back.  This is required to restore the integrity of the
database.
Additionally, to prevent overwriting a database unintentionally, the restore operation
can perform a safety check automatically.  The restore operation fails if:
– The database named in the restore operation already exists on the server and

the database name does not match the database name recorded in the backup
set.

– The database named in the restore operation already exists on the server but it

is not the same database as the database contained in the database backup.
For example, the database names are the same but each database was created
differently.

– One or more files need to be created automatically by the restore operation

(regardless of whether the database already exists) but files with the same file
name as those that need to be created already exist.

These safety checks can be disabled if the intention is to overwrite another
database.