Question: What is the maximum number of partitions in DynamoDB?

Answer

AWS does not publish a fixed maximum number of physical partitions per DynamoDB table. DynamoDB allocates and splits partitions automatically as storage and throughput needs change; you cannot configure a partition count directly.

The frequently repeated "3,000 partitions per table" limit is incorrect. The number 3,000 refers to read capacity units per second that a physical partition can support. A partition also supports up to 1,000 write capacity units per second. Those are capacity units, not necessarily application requests: larger items consume more units.

A partition-key value is not the same thing as a physical partition. Many key values can share a partition, and an item collection without local secondary indexes can span partitions. With an LSI, an item collection has a 10 GB limit, including the relevant index data.

Table and account throughput quotas are separate from partition limits. Increasing an adjustable quota does not remove a hot key, and adding table capacity does not make a single item accept unlimited traffic.

If requests throttle, inspect ThrottlingReasons and CloudWatch metrics. KeyRangeThroughputExceeded points to a hot partition; table or account quota errors need a different response. See partition-key design and DynamoDB throttling.

Sources: AWS quotas and constraints.