Newbie backup question

I just start learning how to use SQL Server 2000.
A question about transaction log backup:
There is a full backup on Sunday night and differential backup from Monday
to Saturday night. Transaction log backup on 9am, 12pm, 3pm, 6pm on
weekdays.
Just wonder is the transaction log at 6pm on Saturday night containing all
transactions from Monday to Friday of the same week ?Nope, the log is emptied each time you do a backup. So the 6PM log backup contains the transactions
produced on sat from 3pm to 6pm (roughly).
--
Tibor Karaszi, SQL Server MVP
Archive at: http://groups.google.com/groups?oi=djq&as ugroup=microsoft.public.sqlserver
"Alan" <alanpltse@.yahoo.com.au> wrote in message news:e7T46DlhDHA.1864@.TK2MSFTNGP10.phx.gbl...
> I just start learning how to use SQL Server 2000.
> A question about transaction log backup:
> There is a full backup on Sunday night and differential backup from Monday
> to Saturday night. Transaction log backup on 9am, 12pm, 3pm, 6pm on
> weekdays.
> Just wonder is the transaction log at 6pm on Saturday night containing all
> transactions from Monday to Friday of the same week ?
>|||To restore your DB to Saturday post log backup you will need
Sunday Full
Friday Differential (Differences between last Full backup and now)
Saturday Logs(9,12,3,6)
BOL has a good example
Differential Backup and Restore
A differential backup creates a copy of all the pages in a database modified
after the last database backup. Differential logs are used primarily in
heavily used systems where a failed database must be brought back online
quickly. Differential backups are smaller than full database backups;
therefore, they have less of an effect on the system while they run.
For example, a site executes a full database backup on Sunday night. A set
of transaction log backups is made every four hours during the day, with the
backups from one day overwriting the backups from the day before. Each night
the site makes a differential backup. If one of the data disks for the
database fails at 9:12 A.M. on Thursday, the site can:
1.. Back up the current transaction log.
2.. Restore the database backup from Sunday night.
3.. Restore the differential backup from Wednesday night to roll the
database forward to that point.
4.. Restore the transaction log backups from 4:00 A.M. and 8:00 A.M. to
roll the database forward to 8:00 A.M.
5.. Restore the log backup taken after the failure. This will roll the
database forward to the time of the failure
--
--
Allan Mitchell (Microsoft SQL Server MVP)
MCSE,MCDBA
www.SQLDTS.com
I support PASS - the definitive, global community
for SQL Server professionals - http://www.sqlpass.org
"Alan" <alanpltse@.yahoo.com.au> wrote in message
news:e7T46DlhDHA.1864@.TK2MSFTNGP10.phx.gbl...
> I just start learning how to use SQL Server 2000.
> A question about transaction log backup:
> There is a full backup on Sunday night and differential backup from Monday
> to Saturday night. Transaction log backup on 9am, 12pm, 3pm, 6pm on
> weekdays.
> Just wonder is the transaction log at 6pm on Saturday night containing all
> transactions from Monday to Friday of the same week ?
>