Interrupted write operation
You should always
properly quit Access by clicking Exit or Close
on the File menu. If a database is open and
writing data when Access is abnormally shut down, the
Jet database engine may mark the database as
suspect/corrupted. This can happen if you manually turn
off the computer without first quitting Windows or if
you lose power. Other situations can occur that do not
shut down Access but that may still interfere with Jet
writing data to the disk while the database is open.
This can happen, for example, when networks experience
data collisions or when disk drives malfunction. If any
of these interruptions occur, Jet may mark the database
as potentially corrupted.
When Jet begins a write operation, it sets a flag, and
it then resets the flag when the operation is complete.
If a write operation is interrupted, the flag remains
set. When you try to open that database again, Jet
determines that the flag is set and reports that the
database is corrupted. In most cases, the data in the
database is not actually corrupted, but the set flag
alerts Jet that corruption may have occurred. In cases
such as this, compacting or repairing the database (or
both) can typically restore the database. Fortunately,
there are ways to determine which user and workstation
was responsible for marking the file as suspect. With
Microsoft Visual Basic for Applications in Access, you
can output a list of users who are logged into a
specific database.
How to determine which
users/workstations are causing the file to be marked as
suspect
When you troubleshoot to determine what is causing
database corruption, you may have to see who is logged
into the database. With Microsoft Visual Basic for
Applications in Access 2002 or in Access 2003, you can
access a list of users who are logged into a specific
database. You can determine who is logged on to a
database by using Microsoft Jet UserRoster in Access.
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more
Faulty networking hardware
Sometimes corruption
can occur without the Jet database engine being
involved. For example, faulty networking hardware can
cause a file to become corrupted. The cause can be one
or more links in the hardware chain between the computer
that the database resides on and the computer that has
the database open. This list includes, but is not
limited to, network interface cards, network cabling,
routers, and hubs.
Hardware-based corruption is typically indicated by .mdb
files that cannot be restored through the use of
compacting, repairing, or Jetcomp. Hardware corruption
will typically recur until the responsible hardware is
repaired or replaced.
Opening and saving the .mdb file
in another program
There is no way to
recover an .mdb file that was opened and then saved in a
different program. For example, you could open and save
an .mdb file in Microsoft Word, but if you were to do
so, the .mdb file could never be recovered, except from
a backup copy. If you accidentally open an .mdb file in
another application, be sure not to save it. It really
serves no purpose to open an .mdb file in another
application because if you do, all you see is a
seemingly random series of characters.
Mismatched Versions of the Jet
Database Engine
If you run different
versions of the Jet Database Engine in your environment,
you can also cause corruption of an Access database.
Different versions of Jet write to the database
differently, and therefore can be the cause of
corruption in a database.
Applies to:
• Microsoft Office Access 2003
• Microsoft Access 2002 Standard Edition |
