My company regularly gives me a flat file – an EXCEL spreadsheet – to analyze. The file typically runs 20,000 or more records. The items are in hierarchical form so that every item is a child of some other item in the same file, and many items are both parents of one set of children and also a child of one or more other items. This generational arrangement runs more than 20 levels. One column on every line has a alphanumeric code that uniquely identifies that item’s parent, but the parent’s ID code is repeated for every child the parent has. I need to pull a unique instance of each parent’s code into a separate table; it’s unimportant whether it is the first, second, last appearance of that code. I built an empty table mimicking the column names and created a unique index (this is how I used to do the same task in 4GL, which we no longer use), but Access vomited the entire 20K+ lines.