I was trying to reattach an object using merge.

The only problem is that I don't have all the fields with me when I try to reattach. I was trying to prevent quering for the object again and also validating what fields have changed.

Basically, I don't want to update the whole row since some columns are dblinked and are not meant for the specific operation that I am working on....

Any way out. Can I build my own reattach operation which would check only the not-null variables and update them if they are changed ?