Copying without corruption

[JJman]

This may sound elementary, but what is the best way to copy a database without causing corruption? The database is only about 4 megs right now. Does doing a simple right click/copy/paste potentially cause problems with the new copy? What about doing a simple click and drag to a new folder? I'm dealing with what appear to be some corruption issues and I'm trying to pin down the cause.

Thanks.

 

[easyedd]

Hi

I have databases that have been 100mb in size which have copied and pasted no problem over multiple drives, what kind of corruption are you getting ie error messages on the copied file or what?

 

[AnanthaP]

Microsoft actually provides an excellent tool to copy the data base (it also compresses the data).

Tools->DtbaseUtilities->CompactDatabase.

This actually makes a compacted copy (or overwrites the same file).

There's also a command line option so youcan put it in a stand-alone script.

We use this method to do scheduled night-shift housekeeping.

End

 

[JJman]

I have two databases that are built with almost identical structure (one database for each of two departments. One is a modified copy of the other). Here are some examples of problems I'm having;

1. There is an ambiguous error message ("there was an error executing the command&quot forbidding more than one person at a time from using a certain form in one DB, though it is not designed to forbid multiple users. The other DB can have multiple users open that same form in their own DB just fine, but they have this error message with two other forms, both of which work fine in the first DB.

2. There is some code that suddenly began working only intermittently. It was working fine for almost a year, but now is unpredictable.

3. The database sometimes locks everyone out saying the database is 'locked on admin. computer (#)', though no one has the database open. One time this message indicated my own computer, though I was logged out and not even here at the time. Someone had to turn off my computer to get the message to go away and allow people in.

4. Periodically Access says the database is not even an .mdb file and must be repaired. I know this can happen for any subsequent user when the previous user shuts down his/her system while the database is still open, but I am not sure this can account for every instance we've experienced.

5. In a third DB I administer, it forbid people to open it and displayed a cryptic message; "The microsoft jet database engine could not find the object 'Databases'. Make sure the object exists and that you spell the name and path name correctly." I have read that sometimes a self-joined table can become corrupt and cause this, but there are no self-joined tables in this DB.

I hope this gives a good summary. Thanks for your help!

 

[JJman]

Thanks Ananthap for your comments, too. I actually have both databases set to compact and repair on close.

 

[psemianonymous]

Some things (like compacting/repairing the database) require that the user has exclusive access. This is not possible in a multiuser environment, and are usually scheduled after hours via Task Scheduler.

Some of your issues definitely look like corrupt databases. Check out the FAQ below to pinpoint your issues and possible solutions, *besides* just "compact/repair".

#2 - depends on what the code does. It could be database corruption. It could be fixed by using /decompile (see FAQ below). Maybe.

#3 - apparently your computer is using the database--also, this depends on what you mean by "logged out". XP logging out doesn't necessarily close the programs/connection - what I mean to say is that in XP you're not really logged out when it seems like you are. This is not a corruption problem, if shutting off your machine "fixed" it.

#4 - corruption. See FAQ

#5 - corruption and/or failed compact. See FAQ



And to answer your original question: no, copying a database doesn't corrupt it. Copying a database *currently in use* CAN corrupt the copy, though I have not witnessed this yet. It's a rare and elusive creature, something like Bigfoot. Except that Bigfoot is a sasquatch and the bug is an odd instance of computer behavior, so they're dissimilar mostly.


I believe I've answered all of your questions, and some you haven't asked (see Bigfoot above).

--
Find common answers using Google Groups:

http://groups.google.com/groups?group=comp.databases.ms-access

Corrupt MDBs FAQ

http://www.granite.ab.ca/access/corruptmdbs.htm

 

[JJman]

Thanks for your help! I'll start looking into all this right away...except maybe Bigfoot... : )

 

[AvGuy]

Don't be too sure it's a software problem. One of the symptoms of RAM going bad is inconsistency in operations. Try a different memory module or a different computer to make sure you don't have a hardware memory problem.

AvGuy