<p>Providing a <code>ClientToken</code> makes the call to <code>ImportTableInput</code> idempotent, meaning that multiple identical calls have the same effect as one single call.</p> <p>A client token is valid for 8 hours after the first request that uses it is completed. After 8 hours, any request with the same client token is treated as a new request. Do not resubmit the same request with the same client token for more than 8 hours, or the result might not be idempotent.</p> <p>If you submit a request with the same client token but a change in other parameters within the 8-hour idempotency window, DynamoDB returns an <code>IdempotentParameterMismatch</code> exception.</p>