Backup and Recovery

  • I guess that the implied full backup was deleted.

    Can unsuccesful, uncommitted or rollback inserts be recovered?

    Steve

    😎

  • Sorry guys for being late but I'd really like my three points, please...

    I said yes you can because it was so obviously implied that a full backup was done.

    Otherwise, is it wrong to assume you actually installed SQL Server and did manage to create a database?

    Please, be serious...

    😀

  • The problem with this QOD is that the answer depends on what you assume is the implied information.

    Either:

    Statement: If I create a database in full recovery mode in SQL Server 2008

    Action: Create db, set full recovery, take full backup

    Statement:then add 1000 records,

    Action: Insert records, check result is successfull

    Statement: then 500 more,

    Action: Insert records, check result is succesfull

    Statement: and then do a log backup,

    Action: take log backup

    Question:can I recover to the point in time between the inserts using the log backup?

    Answer: Yes.

    Or:

    Statement: If I create a database in full recovery mode in SQL Server 2008

    Action: Create db, set full recovery

    Statement:then add 1000 records,

    Action: Insert records

    Statement: then 500 more,

    Action: Insert records

    Statement: and then do a log backup,

    Action: try take log backup...

    Question:can I recover to the point in time between the inserts using the log backup?

    Answer: No.

    So if your standard action si to take a full backup whenever you switch a database to full recovery, then the asnwer is YES, if not, the answer is probably NO.

    I think that there should have been a 3rd option that there was insufficient information to determine the answer.

    Derek

  • The point (tell me if I am wrong...) of QotD is to make us all think a little bit about some technical point(s).

    Not to "trick" the reader...

    That does not present any interest at all... in my opinion.

  • Either we're allowed to assume that ALL steps succeed or that Any step could fail....

    therefore If all steps succeeded then the answer is YES (because you must have taken a full backups)

    or

    if any step has the potential to fail but we are not informed then the answer is NOT ENOUGH INFORMATION TO ANSWER THE QUESTION WITH A BINARY RESPONSE

    MVDBA

  • michael vessey (12/12/2008)


    Either we're allowed to assume that ALL steps succeed or that Any step could fail....

    therefore If all steps succeeded then the answer is YES (because you must have taken a full backups)

    or

    if any step has the potential to fail but we are not informed then the answer is NOT ENOUGH INFORMATION TO ANSWER THE QUESTION WITH A BINARY RESPONSE

    Even if you assume that all steps succeed, you still have insufficient information to answer the question. Because you still have no idea WHEN the full backup was taken.

    And in the given sscenario, taking the full backup after receiving an error message due to the failed log backup makes more sense than any other assumed moment of taking the full backup.


    Hugo Kornelis, SQL Server/Data Platform MVP (2006-2016)
    Visit my SQL Server blog: https://sqlserverfast.com/blog/
    SQL Server Execution Plan Reference: https://sqlserverfast.com/epr/

  • In this case I think the fact the a full backup was explicitly NOT mentioned gave the clue to the expected answer. The issue I believe steve was trying to highlight (and therefore pass on information via the QOD) was that the recovery chain does not start, and therefore point in time recovery is not possible, until a full backup is taken.

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  • If I create a database in full recovery mode in SQL Server 2008, then add 1000 records, then 500 more, and then do a log backup, can I recover to the point in time between the inserts using the log backup?

    ..and then do a log backup.

    well if you then do a log backup you had a full backup.

    It does not say attempt to do a log backup.

    The correct answer was neither yes nor no given the information available so its a bad question.

    Nigel Moore
    ======================

  • OK, I see the argument here, but if you follow the four steps.

    I'll look to reword the question.

  • The point is that step 1, 2, and 3 are not possible without a Full Backup. Step 3 will fail.

    Steve

  • yep, saw that. actually all are possible except the log backup.

    I've edited the post and I'll clean up the question somehow.

  • Doesn't the question say take full back up ?

  • SW_Lindsay (12/22/2008)


    The point is that step 1, 2, and 3 are not possible without a Full Backup. Step 3 will fail.

    Steve

    Amen

    What you don't know won't hurt you but what you know will make you plan to know better
  • Great question, thanks!

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