I just ping support when I want to know partitions. They also told me a little trick. If you create a kinesis stream for your table, the number of shards in the

I just ping support when I want to know partitions. They also told me a little trick. If you create a kinesis stream for your table, the number of shards in the stream is the number of partitions. But you're right part of design for DDB is picking a proper partition key so you don't end up with hot shards.