Click here to monitor SSC
SQLServerCentral is supported by Red Gate Software Ltd.
 
Log in  ::  Register  ::  Not logged in
 
 
 
        
Home       Members    Calendar    Who's On


Add to briefcase «««34567»»»

Backups Expand / Collapse
Author
Message
Posted Friday, April 30, 2010 9:30 AM


SSC-Insane

SSC-InsaneSSC-InsaneSSC-InsaneSSC-InsaneSSC-InsaneSSC-InsaneSSC-InsaneSSC-InsaneSSC-InsaneSSC-InsaneSSC-Insane

Group: General Forum Members
Last Login: Today @ 1:42 AM
Points: 20,799, Visits: 32,717
SQL Dude-467553 (4/30/2010)
I think this question really makes me think. I thought the log backup chain was broken after a full backup based on this I read on MSDN

"If a log backup becomes missing or damaged, start a new log chain by creating a full or differential database backup and then backing up the transaction log to start a new log chain. We recommend that you retain transaction logs backups that come before a missing log backup, in case you ever want to restore the database to a point in time within those backups. For information about how to help protect your backups, see Security Considerations for Backup and Restore (SQL Server)."


If a t-log backup becomes damaged or missing, yes, you need to start a new log chain by performing a full or differential backup. The key here is that the full and differential backups themselves don't BREAK a log chain.



Lynn Pettis

For better assistance in answering your questions, click here
For tips to get better help with Performance Problems, click here
For Running Totals and its variations, click here or when working with partitioned tables
For more about Tally Tables, click here
For more about Cross Tabs and Pivots, click here and here
Managing Transaction Logs

SQL Musings from the Desert Fountain Valley SQL (My Mirror Blog)
Post #913824
Posted Friday, April 30, 2010 9:31 AM


SSC-Addicted

SSC-AddictedSSC-AddictedSSC-AddictedSSC-AddictedSSC-AddictedSSC-AddictedSSC-AddictedSSC-Addicted

Group: General Forum Members
Last Login: Tuesday, November 4, 2014 4:35 AM
Points: 472, Visits: 714
LOL This is just like one of the certification questions. Nice one, Lynn.
Post #913827
Posted Friday, April 30, 2010 9:55 AM


SSC-Insane

SSC-InsaneSSC-InsaneSSC-InsaneSSC-InsaneSSC-InsaneSSC-InsaneSSC-InsaneSSC-InsaneSSC-InsaneSSC-InsaneSSC-Insane

Group: General Forum Members
Last Login: Today @ 1:42 AM
Points: 20,799, Visits: 32,717
Nice Marmot (4/30/2010)
LOL This is just like one of the certification questions. Nice one, Lynn.


Thanks. I guess I'm glad I haven't taken any of the certification tests.



Lynn Pettis

For better assistance in answering your questions, click here
For tips to get better help with Performance Problems, click here
For Running Totals and its variations, click here or when working with partitioned tables
For more about Tally Tables, click here
For more about Cross Tabs and Pivots, click here and here
Managing Transaction Logs

SQL Musings from the Desert Fountain Valley SQL (My Mirror Blog)
Post #913847
Posted Friday, April 30, 2010 10:13 AM


SSCoach

SSCoachSSCoachSSCoachSSCoachSSCoachSSCoachSSCoachSSCoachSSCoachSSCoachSSCoach

Group: General Forum Members
Last Login: Today @ 11:48 AM
Points: 17,948, Visits: 15,944
Steve Jones - Editor (4/30/2010)
CirquedeSQLeil (4/29/2010)
Thanks Lynn.
The part that gets me with these questions is if the hardware failure was enough to corrupt the database and the full backup - it would seem to me that you would be unable to perform a tail log backup. After all the failure had to be severe enough that it was able to corrupt files on different drives / luns. Thus I always have to step back and think a little more about it. It must not have been too severe of a hardware failure because the database was able to be brought back online.


Not necessarily, I think you're caught up in the high end systems. Lots of people have logs/data/bus on one set of disks, often R5. Possible that someone could scribble on a backup and data file and not necessarily the log file. Or enough of the data file to make it necessary to restore.


Good point.




Jason AKA CirqueDeSQLeil
I have given a name to my pain...
MCM SQL Server, MVP


SQL RNNR

Posting Performance Based Questions - Gail Shaw
Post #913868
Posted Friday, April 30, 2010 10:20 AM


SSCoach

SSCoachSSCoachSSCoachSSCoachSSCoachSSCoachSSCoachSSCoachSSCoachSSCoachSSCoach

Group: General Forum Members
Last Login: Today @ 11:48 AM
Points: 17,948, Visits: 15,944
Nice Marmot (4/30/2010)
LOL This is just like one of the certification questions. Nice one, Lynn.


I imagine there are plenty of these types of questions on the current exams. There were plenty for the older versions.




Jason AKA CirqueDeSQLeil
I have given a name to my pain...
MCM SQL Server, MVP


SQL RNNR

Posting Performance Based Questions - Gail Shaw
Post #913875
Posted Friday, April 30, 2010 10:42 AM


Ten Centuries

Ten CenturiesTen CenturiesTen CenturiesTen CenturiesTen CenturiesTen CenturiesTen CenturiesTen Centuries

Group: General Forum Members
Last Login: Tuesday, November 4, 2014 4:59 AM
Points: 1,093, Visits: 2,619
Nice one Lynn. Very good question... and something learned :)



_______________________________________________________________________
For better assistance in answering your questions, click here
Post #913898
Posted Friday, April 30, 2010 10:54 AM


SSC Eights!

SSC Eights!SSC Eights!SSC Eights!SSC Eights!SSC Eights!SSC Eights!SSC Eights!SSC Eights!

Group: General Forum Members
Last Login: Friday, February 4, 2011 7:20 AM
Points: 977, Visits: 1,499
I did just take the cert exam, and I'm glad this one wasn't on it. I too thought that a full backup broke the log chain.

Thanks for a good and educational question.


Tom Garth
Vertical Solutions

"There are three kinds of men. The one that learns by reading. The few who learn by observation. The rest of them have to pee on the electric fence for themselves." -- Will Rogers
Post #913906
Posted Friday, April 30, 2010 11:39 AM
Ten Centuries

Ten CenturiesTen CenturiesTen CenturiesTen CenturiesTen CenturiesTen CenturiesTen CenturiesTen Centuries

Group: General Forum Members
Last Login: Thursday, April 4, 2013 2:37 PM
Points: 1,294, Visits: 46
In the recovery steps use of "latest differential backup" is misleading; I know it does say Tuesday @4pm but shouldn't the "latest differential" be Wednesday @8am? What would be accurate is if it said "latest differential based on Mondays Full Backup"
Post #913955
Posted Friday, April 30, 2010 12:39 PM


SSC-Insane

SSC-InsaneSSC-InsaneSSC-InsaneSSC-InsaneSSC-InsaneSSC-InsaneSSC-InsaneSSC-InsaneSSC-InsaneSSC-InsaneSSC-Insane

Group: General Forum Members
Last Login: Today @ 1:42 AM
Points: 20,799, Visits: 32,717
Shriniket (4/30/2010)
In the recovery steps use of "latest differential backup" is misleading; I know it does say Tuesday @4pm but shouldn't the "latest differential" be Wednesday @8am? What would be accurate is if it said "latest differential based on Mondays Full Backup"


This one has come up a couple of times, so I'll address it. First, sorry if I didn't spell everything out in explicit detail. With that said, it is a matter of interpration based on context. In the context of the scenario, the restore is starting with the Monday night full backup, what is the latest differential backup? Answer, not the one taken at 8:00 AM Wednesday.

If I tell my co-worker I am restoring the Monday night full backup, tell me what the lastest differential backup is while I get this started. I would expect him (or her) to look up the correct file with my having to specify "based on the Mondays Full Backup."

Now, if this individual is a new junior DBA, and wasn't sure, I'd expect them to ask. I'd also be making sure that they learn about backup/restores as they may find themselves having to do it when I'm not available to assist.



Lynn Pettis

For better assistance in answering your questions, click here
For tips to get better help with Performance Problems, click here
For Running Totals and its variations, click here or when working with partitioned tables
For more about Tally Tables, click here
For more about Cross Tabs and Pivots, click here and here
Managing Transaction Logs

SQL Musings from the Desert Fountain Valley SQL (My Mirror Blog)
Post #913998
Posted Friday, April 30, 2010 12:52 PM
Ten Centuries

Ten CenturiesTen CenturiesTen CenturiesTen CenturiesTen CenturiesTen CenturiesTen CenturiesTen Centuries

Group: General Forum Members
Last Login: Thursday, April 4, 2013 2:37 PM
Points: 1,294, Visits: 46
Lynn Pettis (4/30/2010)... With that said, it is a matter of interpration based on context. ...


I think that says it, maybe this could have been a trick question where latest differential did mean Wed 8am which would question one's knowledge of how back ups work ... any how ... please don't apologize, very good question and makes for interesting conversation
Post #914011
« Prev Topic | Next Topic »

Add to briefcase «««34567»»»

Permissions Expand / Collapse