Avaya 38HBK00001SCM Manual Do Utilizador

The backup and restore component of Microsoft® SQL Server™ provides an
important safeguard for protecting critical data stored in SQL Server databases.
Backing up and restoring a database allows for the complete restoration of data
over a wide range of potential system problems:

•

  Media failure

If one or more of the disk drives holding a database fail, you are faced with a
complete loss of data unless you can restore an earlier copy of the data.

•

  User errors

If a user or application either unintentionally or maliciously makes a large
number of invalid modifications to data, the best way to deal with the problem
may be to restore the data to a point in time before the modifications were
made.

•

  Permanent loss of a server

If a server is disabled permanently, or a site is lost to a natural disaster, you
may need to activate a warm standby server or restore a copy of a database to
another server.

Additionally, backing up and restoring databases is useful for non-system problems,
such as moving or copying a database from one server to another.  Backing up a
database from one computer, and restoring the database to another can make a
copy of a database made quickly and easily.

Backing up a database makes a copy of a database, which can be used to restore
the database if it is lost.  Backing up a database copies everything in the database.
A backup operates like a fuzzy snapshot taken of a database :
A database backup records the complete state of the data in the database at the
time the backup operation completes.

Restoring a database backup returns the database to the same state it was in when
the backup was created.  Any incomplete transactions in the database backup,
(transactions that were not complete when the backup operation completed
originally), are rolled back to ensure the database remains consistent.