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The BatchWriteItem operation puts or deletes multiple items in one or more
tables. A single call to BatchWriteItem can transmit up to 16MB of data over
the network, consisting of up to 25 item put or delete operations. While individual
items can be up to 400 KB once stored, it's important to note that an item's representation
might be greater than 400KB while being sent in DynamoDB's JSON format for the API
call. For more details on this distinction, see Naming
Rules and Data Types.
BatchWriteItem cannot update items. If you perform a BatchWriteItem
operation on an existing item, that item's values will be overwritten by the operation
and it will appear like it was updated. To update items, we recommend you use the
UpdateItem action.
The individual PutItem and DeleteItem operations specified in BatchWriteItem
are atomic; however BatchWriteItem as a whole is not. If any requested operations
fail because the table's provisioned throughput is exceeded or an internal processing
failure occurs, the failed operations are returned in the UnprocessedItems
response parameter. You can investigate and optionally resend the requests. Typically,
you would call BatchWriteItem in a loop. Each iteration would check for unprocessed
items and submit a new BatchWriteItem request with those unprocessed items
until all items have been processed.
If none of the items can be processed due to insufficient provisioned throughput
on all of the tables in the request, then BatchWriteItem returns a ProvisionedThroughputExceededException.
If DynamoDB returns any unprocessed items, you should retry the batch operation on those items. However, we strongly recommend that you use an exponential backoff algorithm. If you retry the batch operation immediately, the underlying read or write requests can still fail due to throttling on the individual tables. If you delay the batch operation using exponential backoff, the individual requests in the batch are much more likely to succeed.
For more information, see Batch Operations and Error Handling in the Amazon DynamoDB Developer Guide.
With BatchWriteItem, you can efficiently write or delete large amounts of data,
such as from Amazon EMR, or copy data from another database into DynamoDB. In order
to improve performance with these large-scale operations, BatchWriteItem does
not behave in the same way as individual PutItem and DeleteItem calls
would. For example, you cannot specify conditions on individual put and delete requests,
and BatchWriteItem does not return deleted items in the response.
If you use a programming language that supports concurrency, you can use threads to
write items in parallel. Your application must include the necessary logic to manage
the threads. With languages that don't support threading, you must update or delete
the specified items one at a time. In both situations, BatchWriteItem performs
the specified put and delete operations in parallel, giving you the power of the thread
pool approach without having to introduce complexity into your application.
Parallel processing reduces latency, but each specified put and delete request consumes the same number of write capacity units whether it is processed in parallel or not. Delete operations on nonexistent items consume one write capacity unit.
If one or more of the following is true, DynamoDB rejects the entire batch write operation:
One or more tables specified in the BatchWriteItem request does not exist.
Primary key attributes specified on an item in the request do not match those in the corresponding table's primary key schema.
You try to perform multiple operations on the same item in the same BatchWriteItem
request. For example, you cannot put and delete the same item in the same BatchWriteItem
request.
Your request contains at least two items with identical hash and range keys (which essentially is two put operations).
There are more than 25 requests in the batch.
Any individual item in a batch exceeds 400 KB.
The total request size exceeds 16 MB.
This is an asynchronous operation using the standard naming convention for .NET 4.5 or higher. For .NET 3.5 the operation is implemented as a pair of methods using the standard naming convention of BeginBatchWriteItem and EndBatchWriteItem.
Namespace: Amazon.DynamoDBv2
Assembly: AWSSDK.DynamoDBv2.dll
Version: 3.x.y.z
public abstract Task<BatchWriteItemResponse> BatchWriteItemAsync( BatchWriteItemRequest request, CancellationToken cancellationToken )
Container for the necessary parameters to execute the BatchWriteItem service method.
A cancellation token that can be used by other objects or threads to receive notice of cancellation.
| Exception | Condition |
|---|---|
| InternalServerErrorException | An error occurred on the server side. |
| ItemCollectionSizeLimitExceededException | An item collection is too large. This exception is only returned for tables that have one or more local secondary indexes. |
| ProvisionedThroughputExceededException | Your request rate is too high. The Amazon Web Services SDKs for DynamoDB automatically retry requests that receive this exception. Your request is eventually successful, unless your retry queue is too large to finish. Reduce the frequency of requests and use exponential backoff. For more information, go to Error Retries and Exponential Backoff in the Amazon DynamoDB Developer Guide. |
| RequestLimitExceededException | Throughput exceeds the current throughput quota for your account. Please contact Amazon Web Services Support to request a quota increase. |
| ResourceNotFoundException | The operation tried to access a nonexistent table or index. The resource might not be specified correctly, or its status might not be ACTIVE. |
.NET Core App:
Supported in: 3.1
.NET Standard:
Supported in: 2.0
.NET Framework:
Supported in: 4.5