I did some research about distributed databases, but I still have some questions. I understand there is something called "fragmentation database" but I can't find any help full document for understanding and implementing that.
closed as off-topic by Mark Storey-Smith, RolandoMySQLDBA, Max Vernon, Kin Shah, Michael - sqlbot Mar 7 '14 at 21:49
This question appears to be off-topic. The users who voted to close gave this specific reason:
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Compare a fragmented distributed database with a replicated distributed database. A replicated database would contain all columns and all records on more than one database instance; whereas, the separate instances of a fragmented distributed database do not all contain the same columns and/or records.
Vertical Fragmentation: A vertically-fragmented distributed database would consist of separate instances which do not share all columns / attributes. For example, the database for the sales department might have a column for a customer's interests; however, the database in the accounting department would not need this column.
Horizontal Fragmentation: A horizontally-fragmented distributed database would exist when separate database instances have a similar schema but contain different types of records. For example, a company with two locations East and West might have two similar databases; however, the one instance would only contain customers in the East, the other only customers in the West.