| Gary Andrews 2002-10-05, 9:13 pm |
| FYI about why I am interested.
No defined problem. Trying to determine if there were SQL
Server scenarios which "could" be adversely impacted (and
if there were steps which would eliminate the potientially
adverse effects).
Please allow me to grasp at straws here, just for the sake
of argument.
Assume my SQL Server is running during the night (trying
to provide 7x24) and at 2:00 A.M. the clock on the server
gets set back to 1:00 A.M. Further assume that during this
time you have the normal updates, inserts, selects, etc.
IF log entries are datetime stamped:
I could have log entries with the same datetime stamp (I
don't know if this is a problem or not in case of
transaction backouts, in case of checkpointing the log, in
case of log truncation occuring from a log backup being
taken, etc.).
IF, again for the sake of argument, say transaction log
backups are occuring approximately every 15 minutes. Say I
am using a maintenance plan which creates backup file
names using date and time. Say at the first 1:15 A.M. for
the night I create a backup file (which has the date and
time in its file name). We run until 2:00 and the time
gets set back to 01:00 A.M. Now at 01:05 A.M. we create
another transaction log backup.
At this point should restore/recovery need to be
undertaken, the log backup file date and time stamped at
01:15 needs to be restored followed by the backup date and
time stamped at 01:05. Which is not what you normally
expect.
And again when the log restore occurs, there is still the
issue that we could end up with duplicate date and time
entries (and in my mind there is also an out of sequence
problem which may or may not impact SQL Server).
Another issue.
Say I have a job regularly scheduled to run daily at 1:30
A.M. Don't want it to run twice in one night. Again on the
specific night in question, this job runs. The clock gets
set back to 01:00 A.M. Does the job get run again when the
next 01:30 A.M. gets here?
Say I have a job I want to run every five minutes. Does
this mean that when the clock gets set back from 2:00 to
1:00 A.M., that the job now does not run for the next hour?
I think you get the flavor, so I'll stop here.
Any and all help would be very much appreciated!!
TIA Gary
TIA solart
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