Partition Keys, Sort Keys, and Secondary Indexes
~12 min read
The single most important design decision in DynamoDB — how items are physically organized and looked up.
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Key points
- •Partition Key determines physical storage; queries need it (or an index) to be efficient
- •Low-cardinality or skewed-access partition keys cause 'hot partitions' and throttling
- •Sort Key enables efficient range queries within a shared partition key
- •GSI: new key structure, eventually consistent, addable anytime; LSI: alternate sort key only, defined at creation, supports strong consistency