bitbucket-25253 (6/10/2013)
This discussion of the subject may be of help to you.
As you can see in the third message in this thread I allready mentioned exactly that link. The referenced page is actually only a very rough guide.
If everything seems to be going well, you have obviously overlooked something.
For me it's not obvious what I am overlooking, hence the question.
Because the large number of NULL's, the calculation on the web page is not very accurate. I'll try to come up with a more accurate calculation. Have to count the actual number of Nulls in the variable record fields, I'll need access to the table for this and at the moment I do not have access.
In that way I can see the amount of overhead (quite a lot) which I am missing.
Ben