>quote from MySQL:
>===============
>The outstanding feature of InnoDB tables is also automatic crash
>recovery - in case MySQL shutdown was unclean InnoDB tables will still
>recover to the consistent state, you will not have to check or repair
>them.
>===============
>
>But they are talking normal/common usage, how about in the Worst Case
>Scenarios?
>
>I heard that in some rare case, if InnoDB table was corrupted, there
>are no method to repair them, is that true?

If you have a problem like a hard disk controller writing data to
the wrong sector, thereby blowing holes in your data (or worse,
header information identifying the data), chances are nothing will
fix it but restoring from backups.

>So how about MyISAM vs InnoDB, in Worst Case Scenarios?

In a true Worst Case Scenario, you don't get back anything. Your
server suffers a power surge (it got through the UPS, perhaps because
it was an EMP from a terrorist nuke) and goes down, frying electronics
in the process. You power it back up again, a fire starts, and the
resulting fire takes out all your hardware, all your on-site backups,
and all the people involved with the application.

The resulting fire is detected as a nuclear explosion. Due to
various foul-ups and the TSA letting a bottle of hair gel through
security causing DEFCON 1, the nuclear powers start World War III,
which takes out all of your off-site, on-planet backups, all of the
source code to MySQL, and all the MySQL developers. The EMP from
the nukes takes out any backups you may have had in orbit. Since
humans are now extinct, nobody really cares that your application
doesn't work.

Another worst-case scenario: your hardware suffers a problem. You
try to bring it back up, and it's obvious that the data is all
screwed up. The tape drive or CD/DVD-ROM drive you use to restore
your backups is damaged so that it destroys any backups you insert
in the drive by scratching, stretching, degaussing, or whatever.
Further, any drive you insert the damaged media into is also damaged.
(Didn't this really happen with Zip drives?)

Another worst-case scenario: your hardware develops random,
occasional bit errors that only sometimes cause problems. After a
year of tearing your hair out you finally realize what the problem
is. At this point you have a years worth of backups hopelessly
contaminated with bit errors.