Two Types

Simple: Partition Key (or Hash)

Composite: Partition Key + Sort Key (or Hash + Range)

Primary key should be unique (Cannot be

changed later)

Partition key decides the partition (input to

hash function)

Same partition key items stored together (sorted by

sort key, if it exists)

Choose a partition key that helps you to distribute

items evenly across partitions

Prefer High Cardinality (column with many possible values)

Append a Random Value (if needed)