View Source AWS.DynamoDB (aws-elixir v0.13.3)
Amazon DynamoDB
Amazon DynamoDB is a fully managed NoSQL database service that provides fast and predictable performance with seamless scalability.
DynamoDB lets you offload the administrative burdens of operating and scaling a distributed database, so that you don't have to worry about hardware provisioning, setup and configuration, replication, software patching, or cluster scaling.
With DynamoDB, you can create database tables that can store and retrieve any amount of data, and serve any level of request traffic. You can scale up or scale down your tables' throughput capacity without downtime or performance degradation, and use the Amazon Web Services Management Console to monitor resource utilization and performance metrics.
DynamoDB automatically spreads the data and traffic for your tables over a sufficient number of servers to handle your throughput and storage requirements, while maintaining consistent and fast performance. All of your data is stored on solid state disks (SSDs) and automatically replicated across multiple Availability Zones in an Amazon Web Services Region, providing built-in high availability and data durability.
Link to this section Summary
Functions
This operation allows you to perform batch reads or writes on data stored in DynamoDB, using PartiQL.
The BatchGetItem
operation returns the attributes of one or more items from
one or more tables.
The BatchWriteItem
operation puts or deletes multiple items in one or more
tables.
Creates a backup for an existing table.
Creates a global table from an existing table.
The CreateTable
operation adds a new table to your account.
Deletes an existing backup of a table.
Deletes a single item in a table by primary key.
The DeleteTable
operation deletes a table and all of its items.
Describes an existing backup of a table.
Checks the status of continuous backups and point in time recovery on the specified table.
Returns information about contributor insights for a given table or global secondary index.
Returns the regional endpoint information.
Describes an existing table export.
Returns information about the specified global table.
Describes Region-specific settings for a global table.
Represents the properties of the import.
Returns information about the status of Kinesis streaming.
Returns the current provisioned-capacity quotas for your Amazon Web Services account in a Region, both for the Region as a whole and for any one DynamoDB table that you create there.
Returns information about the table, including the current status of the table, when it was created, the primary key schema, and any indexes on the table.
Describes auto scaling settings across replicas of the global table at once.
Gives a description of the Time to Live (TTL) status on the specified table.
Stops replication from the DynamoDB table to the Kinesis data stream.
Starts table data replication to the specified Kinesis data stream at a timestamp chosen during the enable workflow.
This operation allows you to perform reads and singleton writes on data stored in DynamoDB, using PartiQL.
This operation allows you to perform transactional reads or writes on data stored in DynamoDB, using PartiQL.
Exports table data to an S3 bucket.
The GetItem
operation returns a set of attributes for the item with the given
primary key.
Imports table data from an S3 bucket.
List backups associated with an Amazon Web Services account.
Returns a list of ContributorInsightsSummary for a table and all its global secondary indexes.
Lists completed exports within the past 90 days.
Lists all global tables that have a replica in the specified Region.
Lists completed imports within the past 90 days.
Returns an array of table names associated with the current account and endpoint.
List all tags on an Amazon DynamoDB resource.
Creates a new item, or replaces an old item with a new item.
You must provide the name of the partition key attribute and a single value for that attribute.
Creates a new table from an existing backup.
Restores the specified table to the specified point in time within
EarliestRestorableDateTime
and LatestRestorableDateTime
.
The Scan
operation returns one or more items and item attributes by accessing
every item in a table or a secondary index.
Associate a set of tags with an Amazon DynamoDB resource.
TransactGetItems
is a synchronous operation that atomically retrieves multiple
items from one or more tables (but not from indexes) in a single account and
Region.
TransactWriteItems
is a synchronous write operation that groups up to 100
action requests.
Removes the association of tags from an Amazon DynamoDB resource.
UpdateContinuousBackups
enables or disables point in time recovery for the
specified table.
Updates the status for contributor insights for a specific table or index.
Adds or removes replicas in the specified global table.
Updates settings for a global table.
Edits an existing item's attributes, or adds a new item to the table if it does not already exist.
Modifies the provisioned throughput settings, global secondary indexes, or DynamoDB Streams settings for a given table.
Updates auto scaling settings on your global tables at once.
The UpdateTimeToLive
method enables or disables Time to Live (TTL) for the
specified table.
Link to this section Functions
This operation allows you to perform batch reads or writes on data stored in DynamoDB, using PartiQL.
Each read statement in a BatchExecuteStatement
must specify an equality
condition on all key attributes. This enforces that each SELECT
statement in a
batch returns at most a single item.
The entire batch must consist of either read statements or write statements, you cannot mix both in one batch.
A HTTP 200 response does not mean that all statements in the
BatchExecuteStatement succeeded. Error details for individual statements can be
found under the
Error
field of the BatchStatementResponse
for each statement.
The BatchGetItem
operation returns the attributes of one or more items from
one or more tables.
You identify requested items by primary key.
A single operation can retrieve up to 16 MB of data, which can contain as many
as 100 items. BatchGetItem
returns a partial result if the response size limit
is exceeded, the table's provisioned throughput is exceeded, or an internal
processing failure occurs. If a partial result is returned, the operation
returns a value for UnprocessedKeys
. You can use this value to retry the
operation starting with the next item to get.
If you request more than 100 items, BatchGetItem
returns a
ValidationException
with the message "Too many items requested for the
BatchGetItem call."
For example, if you ask to retrieve 100 items, but each individual item is 300
KB in size, the system returns 52 items (so as not to exceed the 16 MB limit).
It also returns an appropriate UnprocessedKeys
value so you can get the next
page of results. If desired, your application can include its own logic to
assemble the pages of results into one dataset.
If none of the items can be processed due to insufficient provisioned
throughput on all of the tables in the request, then BatchGetItem
returns a
ProvisionedThroughputExceededException
. If at least one of the items is
successfully processed, then BatchGetItem
completes successfully, while
returning the keys of the unread items in UnprocessedKeys
.
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.
By default, BatchGetItem
performs eventually consistent reads on every table
in the request. If you want strongly consistent reads instead, you can set
ConsistentRead
to true
for any or all tables.
In order to minimize response latency, BatchGetItem
may retrieve items in
parallel.
When designing your application, keep in mind that DynamoDB does not return
items in any particular order. To help parse the response by item, include the
primary key values for the items in your request in the ProjectionExpression
parameter.
If a requested item does not exist, it is not returned in the result. Requests for nonexistent items consume the minimum read capacity units according to the type of read. For more information, see Working with Tables in the Amazon DynamoDB Developer Guide.
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 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.
Creates a backup for an existing table.
Each time you create an on-demand backup, the entire table data is backed up. There is no limit to the number of on-demand backups that can be taken.
When you create an on-demand backup, a time marker of the request is cataloged, and the backup is created asynchronously, by applying all changes until the time of the request to the last full table snapshot. Backup requests are processed instantaneously and become available for restore within minutes.
You can call CreateBackup
at a maximum rate of 50 times per second.
All backups in DynamoDB work without consuming any provisioned throughput on the table.
If you submit a backup request on 2018-12-14 at 14:25:00, the backup is guaranteed to contain all data committed to the table up to 14:24:00, and data committed after 14:26:00 will not be. The backup might contain data modifications made between 14:24:00 and 14:26:00. On-demand backup does not support causal consistency.
Along with data, the following are also included on the backups:
Global secondary indexes (GSIs)
Local secondary indexes (LSIs)
Streams
Provisioned read and write capacity
Creates a global table from an existing table.
A global table creates a replication relationship between two or more DynamoDB tables with the same table name in the provided Regions.
This operation only applies to Version 2017.11.29 (Legacy) of global tables. We recommend using Version 2019.11.21 (Current) when creating new global tables, as it provides greater flexibility, higher efficiency and consumes less write capacity than 2017.11.29 (Legacy). To determine which version you are using, see Determining the version. To update existing global tables from version 2017.11.29 (Legacy) to version 2019.11.21 (Current), see Updating global tables.
If you want to add a new replica table to a global table, each of the following conditions must be true:
The table must have the same primary key as all of the other replicas.
The table must have the same name as all of the other replicas.
The table must have DynamoDB Streams enabled, with the stream containing both the new and the old images of the item.
None of the replica tables in the global table can contain any data.
If global secondary indexes are specified, then the following conditions must also be met:
The global secondary indexes must have the same name.
The global secondary indexes must have the same hash key and sort key (if present).
If local secondary indexes are specified, then the following conditions must also be met:
The local secondary indexes must have the same name.
The local secondary indexes must have the same hash key and sort key (if present).
Write capacity settings should be set consistently across your replica tables and secondary indexes. DynamoDB strongly recommends enabling auto scaling to manage the write capacity settings for all of your global tables replicas and indexes.
If you prefer to manage write capacity settings manually, you should provision equal replicated write capacity units to your replica tables. You should also provision equal replicated write capacity units to matching secondary indexes across your global table.
The CreateTable
operation adds a new table to your account.
In an Amazon Web Services account, table names must be unique within each Region. That is, you can have two tables with same name if you create the tables in different Regions.
CreateTable
is an asynchronous operation. Upon receiving a CreateTable
request, DynamoDB immediately returns a response with a TableStatus
of
CREATING
. After the table is created, DynamoDB sets the TableStatus
to
ACTIVE
. You can perform read and write operations only on an ACTIVE
table.
You can optionally define secondary indexes on the new table, as part of the
CreateTable
operation. If you want to create multiple tables with secondary
indexes on them, you must create the tables sequentially. Only one table with
secondary indexes can be in the CREATING
state at any given time.
You can use the DescribeTable
action to check the table status.
Deletes an existing backup of a table.
You can call DeleteBackup
at a maximum rate of 10 times per second.
Deletes a single item in a table by primary key.
You can perform a conditional delete operation that deletes the item if it exists, or if it has an expected attribute value.
In addition to deleting an item, you can also return the item's attribute values
in the same operation, using the ReturnValues
parameter.
Unless you specify conditions, the DeleteItem
is an idempotent operation;
running it multiple times on the same item or attribute does not result in an
error response.
Conditional deletes are useful for deleting items only if specific conditions are met. If those conditions are met, DynamoDB performs the delete. Otherwise, the item is not deleted.
The DeleteTable
operation deletes a table and all of its items.
After a DeleteTable
request, the specified table is in the DELETING
state
until DynamoDB completes the deletion. If the table is in the ACTIVE
state,
you can delete it. If a table is in CREATING
or UPDATING
states, then
DynamoDB returns a ResourceInUseException
. If the specified table does not
exist, DynamoDB returns a ResourceNotFoundException
. If table is already in
the DELETING
state, no error is returned.
This operation only applies to Version 2019.11.21 (Current) of global tables.
DynamoDB might continue to accept data read and write operations, such as
GetItem
and PutItem
, on a table in the DELETING
state until the table
deletion is complete.
When you delete a table, any indexes on that table are also deleted.
If you have DynamoDB Streams enabled on the table, then the corresponding stream
on that table goes into the DISABLED
state, and the stream is automatically
deleted after 24 hours.
Use the DescribeTable
action to check the status of the table.
Describes an existing backup of a table.
You can call DescribeBackup
at a maximum rate of 10 times per second.
Checks the status of continuous backups and point in time recovery on the specified table.
Continuous backups are ENABLED
on all tables at table creation. If point in
time recovery is enabled, PointInTimeRecoveryStatus
will be set to ENABLED.
After continuous backups and point in time recovery are enabled, you can restore
to any point in time within EarliestRestorableDateTime
and
LatestRestorableDateTime
.
LatestRestorableDateTime
is typically 5 minutes before the current time. You
can restore your table to any point in time during the last 35 days.
You can call DescribeContinuousBackups
at a maximum rate of 10 times per
second.
Returns information about contributor insights for a given table or global secondary index.
Returns the regional endpoint information.
This action must be included in your VPC endpoint policies, or access to the DescribeEndpoints API will be denied. For more information on policy permissions, please see Internetwork traffic privacy.
Describes an existing table export.
Returns information about the specified global table.
This operation only applies to Version 2017.11.29 (Legacy) of global tables. We recommend using Version 2019.11.21 (Current) when creating new global tables, as it provides greater flexibility, higher efficiency and consumes less write capacity than 2017.11.29 (Legacy). To determine which version you are using, see Determining the version. To update existing global tables from version 2017.11.29 (Legacy) to version 2019.11.21 (Current), see Updating global tables.
Describes Region-specific settings for a global table.
This operation only applies to Version 2017.11.29 (Legacy) of global tables. We recommend using Version 2019.11.21 (Current) when creating new global tables, as it provides greater flexibility, higher efficiency and consumes less write capacity than 2017.11.29 (Legacy). To determine which version you are using, see Determining the version. To update existing global tables from version 2017.11.29 (Legacy) to version 2019.11.21 (Current), see Updating global tables.
Represents the properties of the import.
describe_kinesis_streaming_destination(client, input, options \\ [])
View SourceReturns information about the status of Kinesis streaming.
Returns the current provisioned-capacity quotas for your Amazon Web Services account in a Region, both for the Region as a whole and for any one DynamoDB table that you create there.
When you establish an Amazon Web Services account, the account has initial quotas on the maximum read capacity units and write capacity units that you can provision across all of your DynamoDB tables in a given Region. Also, there are per-table quotas that apply when you create a table there. For more information, see Service, Account, and Table Quotas page in the Amazon DynamoDB Developer Guide.
Although you can increase these quotas by filing a case at Amazon Web Services Support Center, obtaining the
increase is not instantaneous. The DescribeLimits
action lets you write code
to compare the capacity you are currently using to those quotas imposed by your
account so that you have enough time to apply for an increase before you hit a
quota.
For example, you could use one of the Amazon Web Services SDKs to do the following:
Call
DescribeLimits
for a particular Region to obtain your current account quotas on provisioned capacity there.Create a variable to hold the aggregate read capacity units provisioned for all your tables in that Region, and one to hold the aggregate write capacity units. Zero them both.
Call
ListTables
to obtain a list of all your DynamoDB tables.For each table name listed by
ListTables
, do the following:
* Call `DescribeTable` with the table name.
* Use the data returned by `DescribeTable` to add the
read capacity units and write capacity units provisioned for the table itself to your variables.
* If the table has one or more global secondary indexes
(GSIs), loop over these GSIs and add their provisioned capacity values to your variables as well.
- Report the account quotas for that Region returned by
DescribeLimits
, along with the total current provisioned capacity levels you have calculated.
This will let you see whether you are getting close to your account-level quotas.
The per-table quotas apply only when you are creating a new table. They restrict the sum of the provisioned capacity of the new table itself and all its global secondary indexes.
For existing tables and their GSIs, DynamoDB doesn't let you increase provisioned capacity extremely rapidly, but the only quota that applies is that the aggregate provisioned capacity over all your tables and GSIs cannot exceed either of the per-account quotas.
DescribeLimits
should only be called periodically. You can expect throttling
errors if you call it more than once in a minute.
The DescribeLimits
Request element has no content.
Returns information about the table, including the current status of the table, when it was created, the primary key schema, and any indexes on the table.
This operation only applies to Version 2019.11.21 (Current) of global tables.
If you issue a DescribeTable
request immediately after a CreateTable
request, DynamoDB might return a ResourceNotFoundException
. This is because
DescribeTable
uses an eventually consistent query, and the metadata for your
table might not be available at that moment. Wait for a few seconds, and then
try the DescribeTable
request again.
Describes auto scaling settings across replicas of the global table at once.
This operation only applies to Version 2019.11.21 (Current) of global tables.
Gives a description of the Time to Live (TTL) status on the specified table.
disable_kinesis_streaming_destination(client, input, options \\ [])
View SourceStops replication from the DynamoDB table to the Kinesis data stream.
This is done without deleting either of the resources.
enable_kinesis_streaming_destination(client, input, options \\ [])
View SourceStarts table data replication to the specified Kinesis data stream at a timestamp chosen during the enable workflow.
If this operation doesn't return results immediately, use DescribeKinesisStreamingDestination to check if streaming to the Kinesis data stream is ACTIVE.
This operation allows you to perform reads and singleton writes on data stored in DynamoDB, using PartiQL.
For PartiQL reads (SELECT
statement), if the total number of processed items
exceeds the maximum dataset size limit of 1 MB, the read stops and results are
returned to the user as a LastEvaluatedKey
value to continue the read in a
subsequent operation. If the filter criteria in WHERE
clause does not match
any data, the read will return an empty result set.
A single SELECT
statement response can return up to the maximum number of
items (if using the Limit parameter) or a maximum of 1 MB of data (and then
apply any filtering to the results using WHERE
clause). If LastEvaluatedKey
is present in the response, you need to paginate the result set. If NextToken
is present, you need to paginate the result set and include NextToken
.
This operation allows you to perform transactional reads or writes on data stored in DynamoDB, using PartiQL.
The entire transaction must consist of either read statements or write
statements, you cannot mix both in one transaction. The EXISTS function is an
exception and can be used to check the condition of specific attributes of the
item in a similar manner to ConditionCheck
in the
TransactWriteItems
API.
Exports table data to an S3 bucket.
The table must have point in time recovery enabled, and you can export data from any time within the point in time recovery window.
The GetItem
operation returns a set of attributes for the item with the given
primary key.
If there is no matching item, GetItem
does not return any data and there will
be no Item
element in the response.
GetItem
provides an eventually consistent read by default. If your application
requires a strongly consistent read, set ConsistentRead
to true
. Although a
strongly consistent read might take more time than an eventually consistent
read, it always returns the last updated value.
Imports table data from an S3 bucket.
List backups associated with an Amazon Web Services account.
To list backups for a given table, specify TableName
. ListBackups
returns a
paginated list of results with at most 1 MB worth of items in a page. You can
also specify a maximum number of entries to be returned in a page.
In the request, start time is inclusive, but end time is exclusive. Note that these boundaries are for the time at which the original backup was requested.
You can call ListBackups
a maximum of five times per second.
Returns a list of ContributorInsightsSummary for a table and all its global secondary indexes.
Lists completed exports within the past 90 days.
Lists all global tables that have a replica in the specified Region.
This operation only applies to Version 2017.11.29 (Legacy) of global tables. We recommend using Version 2019.11.21 (Current) when creating new global tables, as it provides greater flexibility, higher efficiency and consumes less write capacity than 2017.11.29 (Legacy). To determine which version you are using, see Determining the version. To update existing global tables from version 2017.11.29 (Legacy) to version 2019.11.21 (Current), see Updating global tables.
Lists completed imports within the past 90 days.
Returns an array of table names associated with the current account and endpoint.
The output from ListTables
is paginated, with each page returning a maximum of
100 table names.
List all tags on an Amazon DynamoDB resource.
You can call ListTagsOfResource up to 10 times per second, per account.
For an overview on tagging DynamoDB resources, see Tagging for DynamoDB in the Amazon DynamoDB Developer Guide.
Creates a new item, or replaces an old item with a new item.
If an item that has the same primary key as the new item already exists in the
specified table, the new item completely replaces the existing item. You can
perform a conditional put operation (add a new item if one with the specified
primary key doesn't exist), or replace an existing item if it has certain
attribute values. You can return the item's attribute values in the same
operation, using the ReturnValues
parameter.
When you add an item, the primary key attributes are the only required attributes.
Empty String and Binary attribute values are allowed. Attribute values of type String and Binary must have a length greater than zero if the attribute is used as a key attribute for a table or index. Set type attributes cannot be empty.
Invalid Requests with empty values will be rejected with a ValidationException
exception.
To prevent a new item from replacing an existing item, use a conditional
expression that contains the attribute_not_exists
function with the name of
the attribute being used as the partition key for the table. Since every record
must contain that attribute, the attribute_not_exists
function will only
succeed if no matching item exists.
For more information about PutItem
, see Working with Items
in the Amazon DynamoDB Developer Guide.
You must provide the name of the partition key attribute and a single value for that attribute.
Query
returns all items with that partition key value. Optionally, you can
provide a sort key attribute and use a comparison operator to refine the search
results.
Use the KeyConditionExpression
parameter to provide a specific value for the
partition key. The Query
operation will return all of the items from the table
or index with that partition key value. You can optionally narrow the scope of
the Query
operation by specifying a sort key value and a comparison operator
in KeyConditionExpression
. To further refine the Query
results, you can
optionally provide a FilterExpression
. A FilterExpression
determines which
items within the results should be returned to you. All of the other results are
discarded.
A Query
operation always returns a result set. If no matching items are found,
the result set will be empty. Queries that do not return results consume the
minimum number of read capacity units for that type of read operation.
DynamoDB calculates the number of read capacity units consumed based on item
size, not on the amount of data that is returned to an application. The number
of capacity units consumed will be the same whether you request all of the
attributes (the default behavior) or just some of them (using a projection
expression). The number will also be the same whether or not you use a
FilterExpression
.
Query
results are always sorted by the sort key value. If the data type of the
sort key is Number, the results are returned in numeric order; otherwise, the
results are returned in order of UTF-8 bytes. By default, the sort order is
ascending. To reverse the order, set the ScanIndexForward
parameter to false.
A single Query
operation will read up to the maximum number of items set (if
using the Limit
parameter) or a maximum of 1 MB of data and then apply any
filtering to the results using FilterExpression
. If LastEvaluatedKey
is
present in the response, you will need to paginate the result set. For more
information, see Paginating the Results
in the Amazon DynamoDB Developer Guide.
FilterExpression
is applied after a Query
finishes, but before the results
are returned. A FilterExpression
cannot contain partition key or sort key
attributes. You need to specify those attributes in the
KeyConditionExpression
.
A Query
operation can return an empty result set and a LastEvaluatedKey
if
all the items read for the page of results are filtered out.
You can query a table, a local secondary index, or a global secondary index. For
a query on a table or on a local secondary index, you can set the
ConsistentRead
parameter to true
and obtain a strongly consistent result.
Global secondary indexes support eventually consistent reads only, so do not
specify ConsistentRead
when querying a global secondary index.
Creates a new table from an existing backup.
Any number of users can execute up to 50 concurrent restores (any type of restore) in a given account.
You can call RestoreTableFromBackup
at a maximum rate of 10 times per second.
You must manually set up the following on the restored table:
Auto scaling policies
IAM policies
Amazon CloudWatch metrics and alarms
Tags
Stream settings
Time to Live (TTL) settings
Restores the specified table to the specified point in time within
EarliestRestorableDateTime
and LatestRestorableDateTime
.
You can restore your table to any point in time during the last 35 days. Any number of users can execute up to 4 concurrent restores (any type of restore) in a given account.
When you restore using point in time recovery, DynamoDB restores your table data to the state based on the selected date and time (day:hour:minute:second) to a new table.
Along with data, the following are also included on the new restored table using point in time recovery:
Global secondary indexes (GSIs)
Local secondary indexes (LSIs)
Provisioned read and write capacity
Encryption settings
All these settings come from the current settings of the source table at the time of restore.
You must manually set up the following on the restored table:
Auto scaling policies
IAM policies
Amazon CloudWatch metrics and alarms
Tags
Stream settings
Time to Live (TTL) settings
Point in time recovery settings
The Scan
operation returns one or more items and item attributes by accessing
every item in a table or a secondary index.
To have DynamoDB return fewer items, you can provide a FilterExpression
operation.
If the total number of scanned items exceeds the maximum dataset size limit of 1
MB, the scan stops and results are returned to the user as a LastEvaluatedKey
value to continue the scan in a subsequent operation. The results also include
the number of items exceeding the limit. A scan can result in no table data
meeting the filter criteria.
A single Scan
operation reads up to the maximum number of items set (if using
the Limit
parameter) or a maximum of 1 MB of data and then apply any filtering
to the results using FilterExpression
. If LastEvaluatedKey
is present in the
response, you need to paginate the result set. For more information, see
Paginating the Results
in the Amazon DynamoDB Developer Guide.
Scan
operations proceed sequentially; however, for faster performance on a
large table or secondary index, applications can request a parallel Scan
operation by providing the Segment
and TotalSegments
parameters. For more
information, see Parallel Scan
in the Amazon DynamoDB Developer Guide.
Scan
uses eventually consistent reads when accessing the data in a table;
therefore, the result set might not include the changes to data in the table
immediately before the operation began. If you need a consistent copy of the
data, as of the time that the Scan
begins, you can set the ConsistentRead
parameter to true
.
Associate a set of tags with an Amazon DynamoDB resource.
You can then activate these user-defined tags so that they appear on the Billing and Cost Management console for cost allocation tracking. You can call TagResource up to five times per second, per account.
For an overview on tagging DynamoDB resources, see Tagging for DynamoDB in the Amazon DynamoDB Developer Guide.
TransactGetItems
is a synchronous operation that atomically retrieves multiple
items from one or more tables (but not from indexes) in a single account and
Region.
A TransactGetItems
call can contain up to 100 TransactGetItem
objects, each
of which contains a Get
structure that specifies an item to retrieve from a
table in the account and Region. A call to TransactGetItems
cannot retrieve
items from tables in more than one Amazon Web Services account or Region. The
aggregate size of the items in the transaction cannot exceed 4 MB.
DynamoDB rejects the entire TransactGetItems
request if any of the following
is true:
A conflicting operation is in the process of updating an item to be read.
There is insufficient provisioned capacity for the transaction to be completed.
There is a user error, such as an invalid data format.
The aggregate size of the items in the transaction exceeded 4 MB.
TransactWriteItems
is a synchronous write operation that groups up to 100
action requests.
These actions can target items in different tables, but not in different Amazon
Web Services accounts or Regions, and no two actions can target the same item.
For example, you cannot both ConditionCheck
and Update
the same item. The
aggregate size of the items in the transaction cannot exceed 4 MB.
The actions are completed atomically so that either all of them succeed, or all of them fail. They are defined by the following objects:
Put
— Initiates aPutItem
operation to write a new item. This structure specifies the primary key of the item to be written, the name of the table to write it in, an optional condition expression that must be satisfied for the write to succeed, a list of the item's attributes, and a field indicating whether to retrieve the item's attributes if the condition is not met.Update
— Initiates anUpdateItem
operation to update an existing item. This structure specifies the primary key of the item to be updated, the name of the table where it resides, an optional condition expression that must be satisfied for the update to succeed, an expression that defines one or more attributes to be updated, and a field indicating whether to retrieve the item's attributes if the condition is not met.Delete
— Initiates aDeleteItem
operation to delete an existing item. This structure specifies the primary key of the item to be deleted, the name of the table where it resides, an optional condition expression that must be satisfied for the deletion to succeed, and a field indicating whether to retrieve the item's attributes if the condition is not met.ConditionCheck
— Applies a condition to an item that is not being modified by the transaction. This structure specifies the primary key of the item to be checked, the name of the table where it resides, a condition expression that must be satisfied for the transaction to succeed, and a field indicating whether to retrieve the item's attributes if the condition is not met.
DynamoDB rejects the entire TransactWriteItems
request if any of the following
is true:
A condition in one of the condition expressions is not met.
An ongoing operation is in the process of updating the same item.
There is insufficient provisioned capacity for the transaction to be completed.
An item size becomes too large (bigger than 400 KB), a local secondary index (LSI) becomes too large, or a similar validation error occurs because of changes made by the transaction.
The aggregate size of the items in the transaction exceeds 4 MB.
There is a user error, such as an invalid data format.
Removes the association of tags from an Amazon DynamoDB resource.
You can call UntagResource
up to five times per second, per account.
For an overview on tagging DynamoDB resources, see Tagging for DynamoDB in the Amazon DynamoDB Developer Guide.
UpdateContinuousBackups
enables or disables point in time recovery for the
specified table.
A successful UpdateContinuousBackups
call returns the current
ContinuousBackupsDescription
. Continuous backups are ENABLED
on all tables
at table creation. If point in time recovery is enabled,
PointInTimeRecoveryStatus
will be set to ENABLED.
Once continuous backups and point in time recovery are enabled, you can restore
to any point in time within EarliestRestorableDateTime
and
LatestRestorableDateTime
.
LatestRestorableDateTime
is typically 5 minutes before the current time. You
can restore your table to any point in time during the last 35 days.
Updates the status for contributor insights for a specific table or index.
CloudWatch Contributor Insights for DynamoDB graphs display the partition key and (if applicable) sort key of frequently accessed items and frequently throttled items in plaintext. If you require the use of Amazon Web Services Key Management Service (KMS) to encrypt this table’s partition key and sort key data with an Amazon Web Services managed key or customer managed key, you should not enable CloudWatch Contributor Insights for DynamoDB for this table.
Adds or removes replicas in the specified global table.
The global table must already exist to be able to use this operation. Any replica to be added must be empty, have the same name as the global table, have the same key schema, have DynamoDB Streams enabled, and have the same provisioned and maximum write capacity units.
This operation only applies to Version 2017.11.29 (Legacy) of global tables. We recommend using Version 2019.11.21 (Current) when creating new global tables, as it provides greater flexibility, higher efficiency and consumes less write capacity than 2017.11.29 (Legacy). To determine which version you are using, see Determining the version. To update existing global tables from version 2017.11.29 (Legacy) to version 2019.11.21 (Current), see Updating global tables.
This operation only applies to Version 2017.11.29 of global tables. If you are using global tables Version 2019.11.21 you can use DescribeTable instead.
Although you can use UpdateGlobalTable
to add replicas and remove replicas in
a single request, for simplicity we recommend that you issue separate requests
for adding or removing replicas.
If global secondary indexes are specified, then the following conditions must also be met:
The global secondary indexes must have the same name.
The global secondary indexes must have the same hash key and sort key (if present).
The global secondary indexes must have the same provisioned and maximum write capacity units.
Updates settings for a global table.
This operation only applies to Version 2017.11.29 (Legacy) of global tables. We recommend using Version 2019.11.21 (Current) when creating new global tables, as it provides greater flexibility, higher efficiency and consumes less write capacity than 2017.11.29 (Legacy). To determine which version you are using, see Determining the version. To update existing global tables from version 2017.11.29 (Legacy) to version 2019.11.21 (Current), see Updating global tables.
Edits an existing item's attributes, or adds a new item to the table if it does not already exist.
You can put, delete, or add attribute values. You can also perform a conditional update on an existing item (insert a new attribute name-value pair if it doesn't exist, or replace an existing name-value pair if it has certain expected attribute values).
You can also return the item's attribute values in the same UpdateItem
operation using the ReturnValues
parameter.
Modifies the provisioned throughput settings, global secondary indexes, or DynamoDB Streams settings for a given table.
This operation only applies to Version 2019.11.21 (Current) of global tables.
You can only perform one of the following operations at once:
Modify the provisioned throughput settings of the table.
Remove a global secondary index from the table.
Create a new global secondary index on the table. After the index begins backfilling, you can use
UpdateTable
to perform other operations.
UpdateTable
is an asynchronous operation; while it is executing, the table
status changes from ACTIVE
to UPDATING
. While it is UPDATING
, you cannot
issue another UpdateTable
request. When the table returns to the ACTIVE
state, the UpdateTable
operation is complete.
Updates auto scaling settings on your global tables at once.
This operation only applies to Version 2019.11.21 (Current) of global tables.
The UpdateTimeToLive
method enables or disables Time to Live (TTL) for the
specified table.
A successful UpdateTimeToLive
call returns the current
TimeToLiveSpecification
. It can take up to one hour for the change to fully
process. Any additional UpdateTimeToLive
calls for the same table during this
one hour duration result in a ValidationException
.
TTL compares the current time in epoch time format to the time stored in the TTL attribute of an item. If the epoch time value stored in the attribute is less than the current time, the item is marked as expired and subsequently deleted.
The epoch time format is the number of seconds elapsed since 12:00:00 AM January 1, 1970 UTC.
DynamoDB deletes expired items on a best-effort basis to ensure availability of throughput for other data operations.
DynamoDB typically deletes expired items within two days of expiration. The exact duration within which an item gets deleted after expiration is specific to the nature of the workload. Items that have expired and not been deleted will still show up in reads, queries, and scans.
As items are deleted, they are removed from any local secondary index and global secondary index immediately in the same eventually consistent way as a standard delete operation.
For more information, see Time To Live in the Amazon DynamoDB Developer Guide.