Copyright | (c) 2013-2018 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 |
Language | Haskell2010 |
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.
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.
Note that if none of the items can be processed due to insufficient provisioned throughput on all of the tables in the request, then BatchWriteItem
will return a ProvisionedThroughputExceededException
.
Important: 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 Elastic MapReduce (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 sameBatchWriteItem
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.
Synopsis
- batchWriteItem :: BatchWriteItem
- data BatchWriteItem
- bwiReturnConsumedCapacity :: Lens' BatchWriteItem (Maybe ReturnConsumedCapacity)
- bwiReturnItemCollectionMetrics :: Lens' BatchWriteItem (Maybe ReturnItemCollectionMetrics)
- bwiRequestItems :: Lens' BatchWriteItem (HashMap Text (NonEmpty WriteRequest))
- batchWriteItemResponse :: Int -> BatchWriteItemResponse
- data BatchWriteItemResponse
- bwirsItemCollectionMetrics :: Lens' BatchWriteItemResponse (HashMap Text [ItemCollectionMetrics])
- bwirsConsumedCapacity :: Lens' BatchWriteItemResponse [ConsumedCapacity]
- bwirsUnprocessedItems :: Lens' BatchWriteItemResponse (HashMap Text (NonEmpty WriteRequest))
- bwirsResponseStatus :: Lens' BatchWriteItemResponse Int
Creating a Request
batchWriteItem :: BatchWriteItem Source #
Creates a value of BatchWriteItem
with the minimum fields required to make a request.
Use one of the following lenses to modify other fields as desired:
bwiReturnConsumedCapacity
- Undocumented member.bwiReturnItemCollectionMetrics
- Determines whether item collection metrics are returned. If set toSIZE
, the response includes statistics about item collections, if any, that were modified during the operation are returned in the response. If set toNONE
(the default), no statistics are returned.bwiRequestItems
- A map of one or more table names and, for each table, a list of operations to be performed (DeleteRequest
orPutRequest
). Each element in the map consists of the following: *DeleteRequest
- Perform aDeleteItem
operation on the specified item. The item to be deleted is identified by aKey
subelement: *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 aPutItem
operation on the specified item. The item to be put is identified by anItem
subelement: *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 aValidationException
exception. 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.
data BatchWriteItem Source #
Represents the input of a BatchWriteItem
operation.
See: batchWriteItem
smart constructor.
Instances
Request Lenses
bwiReturnConsumedCapacity :: Lens' BatchWriteItem (Maybe ReturnConsumedCapacity) Source #
Undocumented member.
bwiReturnItemCollectionMetrics :: 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.
bwiRequestItems :: 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 a DeleteItem
operation on the specified item. The item to be deleted is identified by a Key
subelement: * 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 a PutItem
operation on the specified item. The item to be put is identified by an Item
subelement: * 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 a ValidationException
exception. 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
batchWriteItemResponse Source #
Creates a value of BatchWriteItemResponse
with the minimum fields required to make a request.
Use one of the following lenses to modify other fields as desired:
bwirsItemCollectionMetrics
- A list of tables that were processed byBatchWriteItem
and, for each table, information about any item collections that were affected by individualDeleteItem
orPutItem
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.bwirsConsumedCapacity
- The capacity units consumed by the entireBatchWriteItem
operation. Each element consists of: *TableName
- The table that consumed the provisioned throughput. *CapacityUnits
- The total number of capacity units consumed.bwirsUnprocessedItems
- A map of tables and requests against those tables that were not processed. TheUnprocessedItems
value is in the same form asRequestItems
, so you can provide this value directly to a subsequentBatchGetItem
operation. For more information, seeRequestItems
in the Request Parameters section. EachUnprocessedItems
entry consists of a table name and, for that table, a list of operations to perform (DeleteRequest
orPutRequest
). *DeleteRequest
- Perform aDeleteItem
operation on the specified item. The item to be deleted is identified by aKey
subelement: *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 aPutItem
operation on the specified item. The item to be put is identified by anItem
subelement: *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 aValidationException
exception. 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 emptyUnprocessedItems
map.bwirsResponseStatus
- -- | The response status code.
data BatchWriteItemResponse Source #
Represents the output of a BatchWriteItem
operation.
See: batchWriteItemResponse
smart constructor.
Instances
Response Lenses
bwirsItemCollectionMetrics :: Lens' BatchWriteItemResponse (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.
bwirsConsumedCapacity :: Lens' BatchWriteItemResponse [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.
bwirsUnprocessedItems :: Lens' BatchWriteItemResponse (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 a DeleteItem
operation on the specified item. The item to be deleted is identified by a Key
subelement: * 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 a PutItem
operation on the specified item. The item to be put is identified by an Item
subelement: * 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 a ValidationException
exception. 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.
bwirsResponseStatus :: Lens' BatchWriteItemResponse Int Source #
- - | The response status code.