问在DynamoDB中，当多个读或写请求同时(同一秒)发生时会发生什么？

EN

If your read or write requests exceed the throughput settings for a table,
DynamoDB can throttle that request. DynamoDB can also throttle read requests 
exceeds for an index. 
Throttling prevents your application from consuming too many capacity units.
When a request is throttled, it fails with an HTTP 400 code (Bad Request) and 
a ProvisionedThroughputExceededException. 
The AWS SDKs have built-in support for retrying throttled requests (see Error 
Retries and Exponential Backoff), so you do not need to write this logic 
yourself.