| Copyright | (c) 2013-2021 Brendan Hay |
|---|---|
| License | Mozilla Public License, v. 2.0. |
| Maintainer | Brendan Hay <brendan.g.hay+amazonka@gmail.com> |
| Stability | auto-generated |
| Portability | non-portable (GHC extensions) |
| Safe Haskell | None |
Amazonka.DynamoDB.BatchWriteItem
Description
The BatchWriteItem operation puts or deletes multiple items in one or
more tables. A single call to BatchWriteItem can write up to 16 MB of
data, which can comprise as many as 25 put or delete requests.
Individual items to be written can be as large as 400 KB.
BatchWriteItem cannot update items. To update items, 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
BatchWriteItemrequest 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
BatchWriteItemrequest. For example, you cannot put and delete the same item in the sameBatchWriteItemrequest. - 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.
Synopsis
- data BatchWriteItem = BatchWriteItem' {}
- newBatchWriteItem :: BatchWriteItem
- batchWriteItem_returnConsumedCapacity :: Lens' BatchWriteItem (Maybe ReturnConsumedCapacity)
- batchWriteItem_returnItemCollectionMetrics :: Lens' BatchWriteItem (Maybe ReturnItemCollectionMetrics)
- batchWriteItem_requestItems :: Lens' BatchWriteItem (HashMap Text (NonEmpty WriteRequest))
- data BatchWriteItemResponse = BatchWriteItemResponse' {}
- newBatchWriteItemResponse :: Int -> BatchWriteItemResponse
- batchWriteItemResponse_itemCollectionMetrics :: Lens' BatchWriteItemResponse (Maybe (HashMap Text [ItemCollectionMetrics]))
- batchWriteItemResponse_consumedCapacity :: Lens' BatchWriteItemResponse (Maybe [ConsumedCapacity])
- batchWriteItemResponse_unprocessedItems :: Lens' BatchWriteItemResponse (Maybe (HashMap Text (NonEmpty WriteRequest)))
- batchWriteItemResponse_httpStatus :: Lens' BatchWriteItemResponse Int
Creating a Request
data BatchWriteItem Source #
Represents the input of a BatchWriteItem operation.
See: newBatchWriteItem smart constructor.
Constructors
| BatchWriteItem' | |
Fields
| |
Instances
newBatchWriteItem :: BatchWriteItem Source #
Create a value of BatchWriteItem with all optional fields omitted.
Use generic-lens or optics to modify other optional fields.
The following record fields are available, with the corresponding lenses provided for backwards compatibility:
$sel:returnConsumedCapacity:BatchWriteItem', batchWriteItem_returnConsumedCapacity - Undocumented member.
$sel:returnItemCollectionMetrics:BatchWriteItem', batchWriteItem_returnItemCollectionMetrics - Determines whether item collection metrics are returned. If set to
SIZE, the response includes statistics about item collections, if any,
that were modified during the operation are returned in the response. If
set to NONE (the default), no statistics are returned.
$sel:requestItems:BatchWriteItem', batchWriteItem_requestItems - A map of one or more table names and, for each table, a list of
operations to be performed (DeleteRequest or PutRequest). Each
element in the map consists of the following:
DeleteRequest- Perform aDeleteItemoperation on the specified item. The item to be deleted is identified by aKeysubelement:Key- A map of primary key attribute values that uniquely identify the item. Each entry in this map consists of an attribute name and an attribute value. For each primary key, you must provide all of the key attributes. For example, with a simple primary key, you only need to provide a value for the partition key. For a composite primary key, you must provide values for both the partition key and the sort key.
PutRequest- Perform aPutItemoperation on the specified item. The item to be put is identified by anItemsubelement:Item- A map of attributes and their values. Each entry in this map consists of an attribute name and an attribute value. Attribute values must not be null; string and binary type attributes must have lengths greater than zero; and set type attributes must not be empty. Requests that contain empty values are rejected with aValidationExceptionexception.If you specify any attributes that are part of an index key, then the data types for those attributes must match those of the schema in the table's attribute definition.
Request Lenses
batchWriteItem_returnConsumedCapacity :: Lens' BatchWriteItem (Maybe ReturnConsumedCapacity) Source #
Undocumented member.
batchWriteItem_returnItemCollectionMetrics :: Lens' BatchWriteItem (Maybe ReturnItemCollectionMetrics) Source #
Determines whether item collection metrics are returned. If set to
SIZE, the response includes statistics about item collections, if any,
that were modified during the operation are returned in the response. If
set to NONE (the default), no statistics are returned.
batchWriteItem_requestItems :: Lens' BatchWriteItem (HashMap Text (NonEmpty WriteRequest)) Source #
A map of one or more table names and, for each table, a list of
operations to be performed (DeleteRequest or PutRequest). Each
element in the map consists of the following:
DeleteRequest- Perform aDeleteItemoperation on the specified item. The item to be deleted is identified by aKeysubelement:Key- A map of primary key attribute values that uniquely identify the item. Each entry in this map consists of an attribute name and an attribute value. For each primary key, you must provide all of the key attributes. For example, with a simple primary key, you only need to provide a value for the partition key. For a composite primary key, you must provide values for both the partition key and the sort key.
PutRequest- Perform aPutItemoperation on the specified item. The item to be put is identified by anItemsubelement:Item- A map of attributes and their values. Each entry in this map consists of an attribute name and an attribute value. Attribute values must not be null; string and binary type attributes must have lengths greater than zero; and set type attributes must not be empty. Requests that contain empty values are rejected with aValidationExceptionexception.If you specify any attributes that are part of an index key, then the data types for those attributes must match those of the schema in the table's attribute definition.
Destructuring the Response
data BatchWriteItemResponse Source #
Represents the output of a BatchWriteItem operation.
See: newBatchWriteItemResponse smart constructor.
Constructors
| BatchWriteItemResponse' | |
Fields
| |
Instances
newBatchWriteItemResponse Source #
Create a value of BatchWriteItemResponse with all optional fields omitted.
Use generic-lens or optics to modify other optional fields.
The following record fields are available, with the corresponding lenses provided for backwards compatibility:
$sel:itemCollectionMetrics:BatchWriteItemResponse', batchWriteItemResponse_itemCollectionMetrics - A list of tables that were processed by BatchWriteItem and, for each
table, information about any item collections that were affected by
individual DeleteItem or PutItem operations.
Each entry consists of the following subelements:
ItemCollectionKey- The partition key value of the item collection. This is the same as the partition key value of the item.SizeEstimateRangeGB- An estimate of item collection size, expressed in GB. This is a two-element array containing a lower bound and an upper bound for the estimate. The estimate includes the size of all the items in the table, plus the size of all attributes projected into all of the local secondary indexes on the table. Use this estimate to measure whether a local secondary index is approaching its size limit.The estimate is subject to change over time; therefore, do not rely on the precision or accuracy of the estimate.
$sel:consumedCapacity:BatchWriteItemResponse', batchWriteItemResponse_consumedCapacity - The capacity units consumed by the entire BatchWriteItem operation.
Each element consists of:
TableName- The table that consumed the provisioned throughput.CapacityUnits- The total number of capacity units consumed.
$sel:unprocessedItems:BatchWriteItemResponse', batchWriteItemResponse_unprocessedItems - A map of tables and requests against those tables that were not
processed. The UnprocessedItems value is in the same form as
RequestItems, so you can provide this value directly to a subsequent
BatchGetItem operation. For more information, see RequestItems in
the Request Parameters section.
Each UnprocessedItems entry consists of a table name and, for that
table, a list of operations to perform (DeleteRequest or
PutRequest).
DeleteRequest- Perform aDeleteItemoperation on the specified item. The item to be deleted is identified by aKeysubelement:Key- A map of primary key attribute values that uniquely identify the item. Each entry in this map consists of an attribute name and an attribute value.
PutRequest- Perform aPutItemoperation on the specified item. The item to be put is identified by anItemsubelement:Item- A map of attributes and their values. Each entry in this map consists of an attribute name and an attribute value. Attribute values must not be null; string and binary type attributes must have lengths greater than zero; and set type attributes must not be empty. Requests that contain empty values will be rejected with aValidationExceptionexception.If you specify any attributes that are part of an index key, then the data types for those attributes must match those of the schema in the table's attribute definition.
If there are no unprocessed items remaining, the response contains an
empty UnprocessedItems map.
$sel:httpStatus:BatchWriteItemResponse', batchWriteItemResponse_httpStatus - The response's http status code.
Response Lenses
batchWriteItemResponse_itemCollectionMetrics :: Lens' BatchWriteItemResponse (Maybe (HashMap Text [ItemCollectionMetrics])) Source #
A list of tables that were processed by BatchWriteItem and, for each
table, information about any item collections that were affected by
individual DeleteItem or PutItem operations.
Each entry consists of the following subelements:
ItemCollectionKey- The partition key value of the item collection. This is the same as the partition key value of the item.SizeEstimateRangeGB- An estimate of item collection size, expressed in GB. This is a two-element array containing a lower bound and an upper bound for the estimate. The estimate includes the size of all the items in the table, plus the size of all attributes projected into all of the local secondary indexes on the table. Use this estimate to measure whether a local secondary index is approaching its size limit.The estimate is subject to change over time; therefore, do not rely on the precision or accuracy of the estimate.
batchWriteItemResponse_consumedCapacity :: Lens' BatchWriteItemResponse (Maybe [ConsumedCapacity]) Source #
The capacity units consumed by the entire BatchWriteItem operation.
Each element consists of:
TableName- The table that consumed the provisioned throughput.CapacityUnits- The total number of capacity units consumed.
batchWriteItemResponse_unprocessedItems :: Lens' BatchWriteItemResponse (Maybe (HashMap Text (NonEmpty WriteRequest))) Source #
A map of tables and requests against those tables that were not
processed. The UnprocessedItems value is in the same form as
RequestItems, so you can provide this value directly to a subsequent
BatchGetItem operation. For more information, see RequestItems in
the Request Parameters section.
Each UnprocessedItems entry consists of a table name and, for that
table, a list of operations to perform (DeleteRequest or
PutRequest).
DeleteRequest- Perform aDeleteItemoperation on the specified item. The item to be deleted is identified by aKeysubelement:Key- A map of primary key attribute values that uniquely identify the item. Each entry in this map consists of an attribute name and an attribute value.
PutRequest- Perform aPutItemoperation on the specified item. The item to be put is identified by anItemsubelement:Item- A map of attributes and their values. Each entry in this map consists of an attribute name and an attribute value. Attribute values must not be null; string and binary type attributes must have lengths greater than zero; and set type attributes must not be empty. Requests that contain empty values will be rejected with aValidationExceptionexception.If you specify any attributes that are part of an index key, then the data types for those attributes must match those of the schema in the table's attribute definition.
If there are no unprocessed items remaining, the response contains an
empty UnprocessedItems map.
batchWriteItemResponse_httpStatus :: Lens' BatchWriteItemResponse Int Source #
The response's http status code.