Crashed, damaged database, repairs freeze iMatch

[paulrus]

I recently purchased iMatch 5 after evaluating probably 20 different similar applications.  I already have been working with the trial for several weeks and have started to set things up the way I want them.

Unfortunately yesterday my system crashed and my iMatch database somehow was damaged.  I followed the instructions and ran the database diagnostics, but after 12 hours I came in and iMatch was stuck with (Not Responding) in the title and I couldn't interact with it at all.

What should I do in this type of situation?  I really don't want to lose all the work I've put in to tagging, organizing, etc.

Thanks,

Paul

[Ferdinand]

We understand how you feel.  Sadly, these things can happen.  In my view (Mario may not agree) IMatch is a little more prone to this sort of thing because it's often writing metadata in the background, and so an abnormal termination for any reason can cause corruption.

I don't know what can be done in with your existing database.  Mario will advise whether there's something else to try, although I'm not optimistic.

For future reference, here is what I do to minimise the risk:
. Backup, and do so often.  If you have a backup you can restore it.  This cannot be emphasised enough.
. Don't leave the database open when you're not using it (so power failures for example won't cause corruption).
. Under Preferences > Database there is a Disk Sync Mode that you can set to sync often.   In this mode the database forces the Windows file system to flush the data to the physical disk very often.  My understanding is that this minimises the risk of a discrepancy between what IMatch thinks is in the database and what is actually there.

[sinus]

For future reference, here is what I do to minimise the risk:
. Backup, and do so often.  If you have a backup you can restore it.  This cannot be emphasised enough.
. Don't leave the database open when you're not using it (so power failures for example won't cause corruption).
. Under Preferences > Database there is a Disk Sync Mode that you can set to sync often.   In this mode the database forces the Windows file system to flush the data to the physical disk very often.  My understanding is that this minimises the risk of a discrepancy between what IMatch thinks is in the database and what is actually there.

Paul, I can only emphasize, what Ferdinand wrote.
But I think and hope, you have a backup! I had have quite a lot of crashes (now selcom), but never a corrupted db.

Ferdinand, I was not aware of your preferences- setting. Mine was set to normal, though it is written there, that "fast" is the default.
I have changed this now to "fast", let's look!

[Mario]

There is only one known reason for physical database damage:

1. The database system in IMatch writes data to the disk
2. Windows acknowledges it as 'written' but still has it in the file system cache or the disk cache
3. There is a power failure, spontaneous reboot, disk or network problem that causes the data never reach the disk.

In this case, the database considers the data as written, but the physical file on disk does not match the internal 'image' the database has from the database file. The corrupted/invalid data may be in a seldom used section of the database. Or it may crash IMatch immediately when loading the database. Or the database system spots the error during one of the million database operations IMatch performs in every session.

A corrupted database usually cannot be recovered because the data is just gone or corrupted beyond repair.
There is no protection against such damage. If you experience such problems often, you can tell IMatch to write data more often and to 'flush' it to disk and wait for Windows to actually flush all caches  using the settings available under Edit > Preferences > Database: Disk Sync Mode. The 'Normal' mode is usually a good trade-off between security and speed. Fast is the fastest mode and usually works well unless you work with shaky network connections or in areas with frequent power failures. For W-LAN or similar worse environments, use the "Sync often" mode where the database system flushes data even more often - impacts performance.

The database system used by IMatch is also used by companies like Apple, Google, Adobe and others, and is tested by millions of users in billions of installations each day.