Backup Differential

Hi ,
Can someone provide me futher info about Backup Diffrential ? Is it need
to be perform after the full backup ? How the SQL server detect there is the
changes of the tables ?
1) If I perform a full backup of Pubs mdb in C:\Pubs_Backup . It store
all the data available in the database
2) If I backup differential on the Pubs mdb also , do I need to use back
the same backup name ? If it is , the C:\Pubs_Backup will only consist the
latest updated data.
The original full data will be lost . It is true ?
Travis Tan
Travis
Have you read examples and articles in the BOL? It has very good examples.
"Travis" <Travis@.discussions.microsoft.com> wrote in message
news:8F64EC9D-49AF-4DB7-BDCB-E21F6A5ED700@.microsoft.com...
> Hi ,
> Can someone provide me futher info about Backup Diffrential ? Is it
need
> to be perform after the full backup ? How the SQL server detect there is
the
> changes of the tables ?
> 1) If I perform a full backup of Pubs mdb in C:\Pubs_Backup . It store
> all the data available in the database
> 2) If I backup differential on the Pubs mdb also , do I need to use
back
> the same backup name ? If it is , the C:\Pubs_Backup will only consist the
> latest updated data.
> The original full data will be lost . It is true ?
>
> --
> Travis Tan
|||Travis wrote:
> Hi ,
> Can someone provide me futher info about Backup Diffrential ? Is it need
> to be perform after the full backup ? How the SQL server detect there is the
> changes of the tables ?
> 1) If I perform a full backup of Pubs mdb in C:\Pubs_Backup . It store
> all the data available in the database
> 2) If I backup differential on the Pubs mdb also , do I need to use back
> the same backup name ? If it is , the C:\Pubs_Backup will only consist the
> latest updated data.
> The original full data will be lost . It is true ?
>
>
look in BooksOnLine (BOL), it's all there
|||Travis,
In order to restore the db, you will need a full backup and the
differential, if there is one, plus all log backups after the diff one, or if
the sequence of log backups have not been broken, you can use the last full
backup and all transactions log backups. But time is precious and
differential backups help you save time.
A diffenrential backup is useful when the full backup of your db take long
time, so if you need to backup your data twice daily and the full backup take
12 hours, you can take one full backup once a week and two diff backups
daily, saving all changes from the last full backup.
As the others members said, BOL has good samples. You can also find some
good articles about this theme in Tibor's web page.
http://www.karaszi.com/SQLServer/articles.asp
AMB
"Travis" wrote:

> Hi ,
> Can someone provide me futher info about Backup Diffrential ? Is it need
> to be perform after the full backup ? How the SQL server detect there is the
> changes of the tables ?
> 1) If I perform a full backup of Pubs mdb in C:\Pubs_Backup . It store
> all the data available in the database
> 2) If I backup differential on the Pubs mdb also , do I need to use back
> the same backup name ? If it is , the C:\Pubs_Backup will only consist the
> latest updated data.
> The original full data will be lost . It is true ?
>
> --
> Travis Tan
|||Differential Database Backups
A differential database backup records only the data that has changed since
the last database backup. You can make more frequent backups because
differential database backups are smaller and faster than database backups.
Making frequent backups decreases your risk of losing data.
Note If you have created any file backups since the last full database
backup, those files will be scanned by Microsoft? SQL Server? 2000 at the
beginning of a differential database backup. This may cause some degradation
of performance in the differential database backup. For more information, see
Using File Backups.
You use differential database backups to restore the database to the point
at which the differential database backup was completed. To recover to the
exact point of failure, you must use transaction log backups. For more
information, see Transaction Log Backups.
Consider using differential database backups when:
Only a relatively small portion of the data in the database has changed
since the last database backup. Differential database backups are
particularly effective if the same data is modified many times.
You are using the Simple Recovery model and want more frequent backups, but
don't want to do frequent full database backups.
You are using the Full or Bulk-Logged Recovery model and want to minimize
the time it takes to roll forward transaction log backups when restoring a
database.
A recommended process for implementing differential database backups is:
Create regular database backups.
Create a differential database backup periodically between database backups,
such as every four hours or more for highly active systems.
If using Full or Bulk-Logged Recovery, create transaction log backups more
frequently than differential database backups, such as every 30 minutes.
The sequence for restoring differential database backups is:
Restore the most recent database backup.
Restore the last differential database backup.
Apply all transaction log backups created after the last differential
database backup was created if you use Full or Bulk-Logged Recovery.
For more information on differential database backups go here:
http://msdn.microsoft.com/library/de...kprst_7tv7.asp
"Travis" wrote:

> Hi ,
> Can someone provide me futher info about Backup Diffrential ? Is it need
> to be perform after the full backup ? How the SQL server detect there is the
> changes of the tables ?
> 1) If I perform a full backup of Pubs mdb in C:\Pubs_Backup . It store
> all the data available in the database
> 2) If I backup differential on the Pubs mdb also , do I need to use back
> the same backup name ? If it is , the C:\Pubs_Backup will only consist the
> latest updated data.
> The original full data will be lost . It is true ?
>
> --
> Travis Tan