According to the manual: If you have created a new log sequence after
recovery, any tablespace backup images on the old log sequence are
invalid. This is usually recognized at restore time.

Could someone let me know 'how' this is recognized at restore time?

TIA
Raquel.

Raquel <raquel_rodriguezus@yahoo.com> wrote:
> According to the manual: If you have created a new log sequence after
> recovery, any tablespace backup images on the old log sequence are
> invalid. This is usually recognized at restore time.
>
> Could someone let me know 'how' this is recognized at restore time?

In the header of each log file, there is information that uniquely
indentifies which log chain it belongs to. This way you can't take a
log from one chain and replay it as part of a rollforward along a
different chain.

Similarly, when a backup is taken, it stores information about what log
chain is current at the time. If you use this backup in a tablespace
restore, db2 will verify that the same log chain is active as was active
at backup time.

dave

Thanks David. Didn't find this piece of information in any IBM Manual.
If there is some place where IBM has documented this, could you let me
know because it might have many other answers to my naive doubts.

Regards,
Raquel.

Raquel <raquel_rodriguezus@yahoo.com> wrote:
> Thanks David. Didn't find this piece of information in any IBM Manual.
> If there is some place where IBM has documented this, could you let me
> know because it might have many other answers to my naive doubts.

The documentation tends to describe how features work from the db admin's
point of view. Internal details about how the features work are generally
not documented. Some of this stuff is dicussed in white papers and at
conferences, though.

dave