ACC: How Microsoft Access Deletes Objects from a Database (90129)
The information in this article applies to:
- Microsoft Access 1.0
- Microsoft Access 1.1
- Microsoft Access 2.0
- Microsoft Access for Windows 95 7.0
- Microsoft Access 97
This article was previously published under Q90129 Novice: Requires knowledge of the user interface on single-user computers.
SUMMARY
This article describes what happens internally in Microsoft Access when you
delete an object (a table, a form, a query, and so on) from a database.
MORE INFORMATION
When you delete an object from the Database window, it is not physically
deleted from the database at that moment. Instead, it is renamed to a
temporary name (for example, ~TMPCLP1) and hidden, so that it disappears
from the Database window. The renaming operation occurs very quickly,
regardless of the object's size. The hidden object is physically deleted
from the database as soon as you take any action other than the Undo
Deletion action.
Microsoft Access deletes objects in this manner so that you can undo an
accidental deletion, but only if you have not performed any other action
that makes "undoing" an object deletion impossible. Microsoft Access can
undo commands only one level back; it cannot queue up multiple commands to
undo.
Because the physical deletion of the object occurs when you perform the
next action rather than at the moment you choose the Delete command, your
computer may appear to stop responding (hang) while it performs the delete
operation. If the object is large enough, the deletion may take some time.
NOTE: If you restart your computer before the deletion is complete, the
hidden temporary object remains in the database, wasting space. To remove
hidden objects such as this, compact the database.
Speed of Deletion
The time it takes to delete an object depends on how large it is and how
fast the computer is that you are using. Smaller objects are deleted
faster than larger ones. If the database that contains the object to be
deleted is on a network file server, the deletion will take longer.
How long an object deletion will take cannot be accurately predicted
because the speed of deleting the object is also affected by the nature of
the data contained in it. (For example, with tables, number columns are
deleted more quickly than Memo and OLE columns.)
Internally, Microsoft Access does not provide a status callback for object
deletion; therefore, a progress indicator in the status bar is not
possible. Because there is no progress indicator, Microsoft Access does
not yield to the system until the object deletion procedure is complete.
Therefore, you cannot abort the operation or switch to another application
while the object is being deleted.
REFERENCES
For more information about the Undo option, search on the word "undo"
using the Microsoft Access Help Index, or ask the Microsoft Access 97
Office Assistant.
Modification Type: | Major | Last Reviewed: | 5/28/2003 |
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Keywords: | kbinfo kbusage KB90129 |
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