Question: How do you parallelize requests in DynamoDB?

Answer

Run independent DynamoDB requests concurrently with a bounded worker pool, async tasks or batch APIs. Increasing concurrency can improve throughput, but it cannot bypass partition, table or account limits.

Choose the mechanism for the operation:

• BatchGetItem retrieves up to 100 items by complete key. Retry UnprocessedKeys, and do not assume response order matches request order.
• BatchWriteItem puts or deletes up to 25 items per call. It does not update items, accept per-item conditions or make the whole batch atomic. Retry UnprocessedItems with backoff.
• Concurrent Query calls can read different partition-key values. Paginate each query independently.
• Parallel Scan assigns workers distinct Segment values with the same TotalSegments. Each worker must paginate its own segment.

Bound the amount of in-flight work instead of launching every request at once. Reuse SDK clients where supported, and monitor latency, consumed capacity and ThrottlingReasons. A hot key can still throttle even when aggregate table capacity is available.

You choose logical keys, not physical storage partitions. For large analytical extracts, managed export to S3 can avoid consuming table read capacity. Use an orchestration or ETL service when a resumable job is needed rather than relying on an unbounded script.

See batch operations and throttling.

Source: AWS batch operations.