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Evolving a NoSQL Database Schema
In a NoSQL environment, Entity Manager organizes the physical distribution of data to support efficient query operations.
On the other hand, this should feel familiar: just as with userId above, we can use the hash keys on our new indexes to constrain the result sets down to just the User records we’re interested in. Entity Manager solves this problem by applying a hash function to the record’s unique identifier (in this case userId or email), and constraining the output to a limited set of possible values. To support a DynamoDB implementation, therefore, the Entity Manager configuration should always include both the hash and range keys of the record in the index definition.
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