>What is the recommended way to design a database to deal with the following situation:
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>A school system has a central database. Data is entered at member schools either directly into the master DB or into detached copies of the master DB. If copies are used, they are to be synchronized periodically with the master DB.
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>What method do you recommend to avoid creating duplicate keys? I would prefer that keys are single fields but not GUIDs, because those are just too long.
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>What procedure needs to be followed to synchronize data?


For keys I would use a field long enough to hold the userid plus 10 characters and use the userid + the output of sys(2015) which will give you a 10 character unique string. The userid is just to make sure it's unique across machines (since it's only guaranteed unique on one machine). You could also use sys(0)+sys(2015) which should give you a unique key for each and every record.