UtterAccess.com
X   Site Message
(Message will auto close in 2 seconds)

Welcome to UtterAccess! Please ( Login   or   Register )

Custom Search
 
   Reply to this topicStart new topic
> Bad Data Corruption, Access 2003    
 
   
youngb
post Nov 10 2017, 09:30 AM
Post#1



Posts: 517
Joined: 2-September 03
From: Galway, Ireland


Hi,

I have been using access now for about 20 years for a large range of application, and the amount of corrupt data and records would be rare,
and would be only one record in one table but recently I have had three cases of data corruption like I have never come across before, and just one more this morning,
The client is using Access 2003 runtime on Windows 7 for the last 5 years with no problems before this,
I was not able to attached the data file because they were too large over 50 mb, and the only way to reduce the size is too compact and repair.

This morning it was a case of data corruption of 66 records in one table see attached jpeg, and on this occasion I can't even do a 'Compact and Repair' even after I have remove the offending table.
Now I do have a back up from this morning, but my question is does anybody have any idea of what would cause that kind of corruption, in a backend data file,
The application has individual frontends on the C drive of each computer link back to a server which has been set up by a professional

In my experience the most common source of date file corruption is when some user stops the process in the middle of a write to the data by shutting down the pc or using 'Control Alt Delete' which can be repaired by a 'Compact and repair' the other source could be the 'Net Work' connection but it is really hard to figure what would cause this kind of large scale corruption, on the previous occasion I have since done a compact and repair on the data and the users have re-entered the data the lost about 120 records but on this occasion I can't even do that.

Thanks in advance for any suggestion.

Brian
Attached File(s)
Attached File  Corrupt_Deliveries_1.jpg ( 456K )Number of downloads: 16
Attached File  Corrupt_Deliveries_2.jpg ( 453.5K )Number of downloads: 14
 
Go to the top of the page
 
John Vinson
post Nov 10 2017, 09:36 PM
Post#2


UtterAccess VIP
Posts: 4,143
Joined: 6-January 07
From: Parma, Idaho, US


If you have not done so already, I'd (strongly) suggest creating a completely new, empty backend database (all users should be locked out); import all the tables from a working copy (current if possible, most recent working backup if not); compact and repair this NEW database; and relink to it. There are some kinds of corruption which C&R is unable to fix.

You should also be sure that all the users are connecting over a fast, stable, wired LAN - wireless connections, VPN, or <shudder> links over the Internet can and will cause corruption and data loss. If users need to communicate from remote sites (not on the corporate LAN) then you should strongly consider having them use terminal emulation (Citrix or the like) to connect to a box on the LAN, containing that user's copy of the frontend in a private directory, linked to the shared backend.

--------------------
John W. Vinson
Wysard of Information
Go to the top of the page
 
youngb
post Nov 13 2017, 05:33 AM
Post#3



Posts: 517
Joined: 2-September 03
From: Galway, Ireland


Hi John,

Thanks for the response,

that is indeed what I did, excluding the two corrupt tables, for the two corrupt tables I appended the good data to a new table and the imported in, so I am back up and running,
but I am more concerned about the fact that this is not a one off and has occurred 4 times in the last six months,
to answer your question, no they are not using and wireless(I have had to back track on a Wireless set up before as it was not just reliable enough in a manufacturing environment) and is all using fast stable, wired lan,
the only thing that does stand out is there are using a Nas drive as the server, (Nas Server), I am a little suspect to the fact that this occurred on 3 out of the 4 occasions on a Friday morning,
I know there are a lot of back up's running, I am wondering could this be caused by some backup that would lock the mdb backend file so the edit records can't write back to the database.
It has to be something like this as the 67 records that are corrupt were of course the ones that were been edited that morning.

As a process of elimination and I am considering moving the backend database file to a shared drive on a different pc just to see if this will solve the problem.

Regards
Brian
Go to the top of the page
 


Custom Search
RSSSearch   Top   Lo-Fi    11th December 2017 - 11:33 PM