I encountered a duplicates problem where I couldn't find a solution.
From a certain electronic banking system downloads of account data are
possible, up to 1 year back. They contain basic data like date, amount +/-,
acount numbers from/to, name of opposite party, sometimes a message. There
is *no* unique identifier per record ;=(((((((((
The period of the download can be chosen freely which allows overlaps of up
to almost a year. I made a test with my own historical electronic banking
data from an off-line system (with modem connection), being 13070 contiguous
records over 11 years. I ...