I have decided to write about SSAS 2008 errors that I come across occasionally, either by my own hand or things that I see my customers doing from time to time. In particular, if I’ve had trouble finding the resolution anywhere else on the Internet, I think it’s important to share my resolution to save other people some time!
Issue: One bugbear is the following error message:
Errors in the back-end database access module. The size specified for a binding was too small, resulting in one or more column values being truncated.
This is my most un-favourite error message of all time. If you get this error message, it can be difficult to identify where the issue is. This error seems to arise if you do any changes to a view or table underlying the DSV, which can arise in a mismatch.
The error message gives you details of the offending column. The fix seems to be to re-open the DSV, close it again, then reprocess dimension, then cube. If not, you can try to wade through the code version of the DSV and see where the mis-match is.
It might be worth having a look at the health of the server. I have noticed that I don’t get this error message on some machines. However, I have had this error message repeatedly on one machine that belonged to one of my customers, which was a server that’s slowly grinding to a halt. Since it wasn’t my machine, I wasn’t in a position to do very much except try and get their IT support to look at it.
It seems that prevention is the best way to get rid of this error message. Having had this error message at the worst times, I now try and prevent it by using Views in the DSV. For every column in the view, I specifically cast it as a particular type in the view.
Sometimes it’s been near impossible to work out where the issue is, so I’ve simply had to start again by casting every column in the cube as a type, and then re-creating a new cube using the dimensions etc that I’ve already created. It’s not great but it can sometimes be quicker just to do this.
I hope that this helps!