One or more substitution tokens for attribute names in an expression. The following are some use cases for using ExpressionAttributeNames:

• To access an attribute whose name conflicts with a DynamoDB reserved word.
• To create a placeholder for repeating occurrences of an attribute name in an expression.
• To prevent special characters in an attribute name from being misinterpreted in an expression.

Use the # character in an expression to dereference an attribute name. For example, consider the following attribute name:

• Percentile

The name of this attribute conflicts with a reserved word, so it cannot be used directly in an expression. (For the complete list of reserved words, see Reserved Words in the Amazon DynamoDB Developer Guide). To work around this, you could specify the following for ExpressionAttributeNames:

• {"#P":"Percentile"}

You could then use this substitution in an expression, as in this example:

• #P = :val

Tokens that begin with the : character are /expression attribute values/, which are placeholders for the actual value at runtime.

For more information on expression attribute names, see Specifying Item Attributes in the Amazon DynamoDB Developer Guide.

Use ReturnValues if you want to get the item attributes as they appeared before they were updated with the PutItem request. For PutItem, the valid values are:

• NONE - If ReturnValues is not specified, or if its value is NONE, then nothing is returned. (This setting is the default for ReturnValues.)
• ALL_OLD - If PutItem overwrote an attribute name-value pair, then the content of the old item is returned.

The ReturnValues parameter is used by several DynamoDB operations; however, PutItem does not recognize any values other than NONE or ALL_OLD.

One or more values that can be substituted in an expression.

Use the : (colon) character in an expression to dereference an attribute value. For example, suppose that you wanted to check whether the value of the ProductStatus attribute was one of the following:

Available | Backordered | Discontinued

You would first need to specify ExpressionAttributeValues as follows:

{ ":avail":{"S":"Available"}, ":back":{"S":"Backordered"}, ":disc":{"S":"Discontinued"} }

You could then use these values in an expression, such as this:

ProductStatus IN (:avail, :back, :disc)

For more information on expression attribute values, see Condition Expressions in the Amazon DynamoDB Developer Guide.

Undocumented member.

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.

A condition that must be satisfied in order for a conditional PutItem operation to succeed.

An expression can contain any of the following:

• Functions: attribute_exists | attribute_not_exists | attribute_type | contains | begins_with | size

  These function names are case-sensitive.

• Comparison operators: = | <> | < | > | <= | >= | BETWEEN | IN
• Logical operators: AND | OR | NOT

For more information on condition expressions, see Condition Expressions in the Amazon DynamoDB Developer Guide.

This is a legacy parameter. Use ConditionExpression instead. For more information, see ConditionalOperator in the Amazon DynamoDB Developer Guide.

This is a legacy parameter. Use ConditionExpression instead. For more information, see Expected in the Amazon DynamoDB Developer Guide.

The name of the table to contain the item.

A map of attribute name/value pairs, one for each attribute. Only the primary key attributes are required; you can optionally provide other attribute name-value pairs for the item.

You must provide all of the attributes for the primary key. 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 both values for both the partition key and the sort key.

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.

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.

For more information about primary keys, see Primary Key in the Amazon DynamoDB Developer Guide.

Each element in the Item map is an AttributeValue object.

Information about item collections, if any, that were affected by the PutItem operation. ItemCollectionMetrics is only returned if the ReturnItemCollectionMetrics parameter was specified. If the table does not have any local secondary indexes, this information is not returned in the response.

Each ItemCollectionMetrics element consists of:

• ItemCollectionKey - The partition key value of the item collection. This is the same as the partition key value of the item itself.

• SizeEstimateRangeGB - An estimate of item collection size, in gigabytes. This value 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 that 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.

The capacity units consumed by the PutItem operation. The data returned includes the total provisioned throughput consumed, along with statistics for the table and any indexes involved in the operation. ConsumedCapacity is only returned if the ReturnConsumedCapacity parameter was specified. For more information, see Read/Write Capacity Mode in the Amazon DynamoDB Developer Guide.

The attribute values as they appeared before the PutItem operation, but only if ReturnValues is specified as ALL_OLD in the request. Each element consists of an attribute name and an attribute value.

The response's http status code.

One or more substitution tokens for attribute names in an expression. The following are some use cases for using ExpressionAttributeNames:

• To access an attribute whose name conflicts with a DynamoDB reserved word.
• To create a placeholder for repeating occurrences of an attribute name in an expression.
• To prevent special characters in an attribute name from being misinterpreted in an expression.

Use the # character in an expression to dereference an attribute name. For example, consider the following attribute name:

• Percentile

The name of this attribute conflicts with a reserved word, so it cannot be used directly in an expression. (For the complete list of reserved words, see Reserved Words in the Amazon DynamoDB Developer Guide). To work around this, you could specify the following for ExpressionAttributeNames:

• {"#P":"Percentile"}

You could then use this substitution in an expression, as in this example:

• #P = :val

Tokens that begin with the : character are /expression attribute values/, which are placeholders for the actual value at runtime.

For more information on expression attribute names, see Specifying Item Attributes in the Amazon DynamoDB Developer Guide.

Use ReturnValues if you want to get the item attributes as they appeared before they were deleted. For DeleteItem, the valid values are:

• NONE - If ReturnValues is not specified, or if its value is NONE, then nothing is returned. (This setting is the default for ReturnValues.)
• ALL_OLD - The content of the old item is returned.

The ReturnValues parameter is used by several DynamoDB operations; however, DeleteItem does not recognize any values other than NONE or ALL_OLD.

One or more values that can be substituted in an expression.

Use the : (colon) character in an expression to dereference an attribute value. For example, suppose that you wanted to check whether the value of the ProductStatus attribute was one of the following:

Available | Backordered | Discontinued

You would first need to specify ExpressionAttributeValues as follows:

{ ":avail":{"S":"Available"}, ":back":{"S":"Backordered"}, ":disc":{"S":"Discontinued"} }

You could then use these values in an expression, such as this:

ProductStatus IN (:avail, :back, :disc)

For more information on expression attribute values, see Condition Expressions in the Amazon DynamoDB Developer Guide.

Undocumented member.

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.

A condition that must be satisfied in order for a conditional DeleteItem to succeed.

An expression can contain any of the following:

• Functions: attribute_exists | attribute_not_exists | attribute_type | contains | begins_with | size

  These function names are case-sensitive.

• Comparison operators: = | <> | < | > | <= | >= | BETWEEN | IN
• Logical operators: AND | OR | NOT

For more information about condition expressions, see Condition Expressions in the Amazon DynamoDB Developer Guide.

This is a legacy parameter. Use ConditionExpression instead. For more information, see ConditionalOperator in the Amazon DynamoDB Developer Guide.

This is a legacy parameter. Use ConditionExpression instead. For more information, see Expected in the Amazon DynamoDB Developer Guide.

The name of the table from which to delete the item.

A map of attribute names to AttributeValue objects, representing the primary key of the item to delete.

For the primary key, you must provide all of the 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.

Information about item collections, if any, that were affected by the DeleteItem operation. ItemCollectionMetrics is only returned if the ReturnItemCollectionMetrics parameter was specified. If the table does not have any local secondary indexes, this information is not returned in the response.

Each ItemCollectionMetrics element consists of:

• ItemCollectionKey - The partition key value of the item collection. This is the same as the partition key value of the item itself.

• SizeEstimateRangeGB - An estimate of item collection size, in gigabytes. This value 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 that 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.

The capacity units consumed by the DeleteItem operation. The data returned includes the total provisioned throughput consumed, along with statistics for the table and any indexes involved in the operation. ConsumedCapacity is only returned if the ReturnConsumedCapacity parameter was specified. For more information, see Provisioned Mode in the Amazon DynamoDB Developer Guide.

A map of attribute names to AttributeValue objects, representing the item as it appeared before the DeleteItem operation. This map appears in the response only if ReturnValues was specified as ALL_OLD in the request.

The response's http status code.

One or more substitution tokens for attribute names in an expression. The following are some use cases for using ExpressionAttributeNames:

• To access an attribute whose name conflicts with a DynamoDB reserved word.
• To create a placeholder for repeating occurrences of an attribute name in an expression.
• To prevent special characters in an attribute name from being misinterpreted in an expression.

Use the # character in an expression to dereference an attribute name. For example, consider the following attribute name:

• Percentile

The name of this attribute conflicts with a reserved word, so it cannot be used directly in an expression. (For the complete list of reserved words, see Reserved Words in the Amazon DynamoDB Developer Guide.) To work around this, you could specify the following for ExpressionAttributeNames:

• {"#P":"Percentile"}

You could then use this substitution in an expression, as in this example:

• #P = :val

Tokens that begin with the : character are /expression attribute values/, which are placeholders for the actual value at runtime.

For more information about expression attribute names, see Specifying Item Attributes in the Amazon DynamoDB Developer Guide.

Use ReturnValues if you want to get the item attributes as they appear before or after they are updated. For UpdateItem, the valid values are:

• NONE - If ReturnValues is not specified, or if its value is NONE, then nothing is returned. (This setting is the default for ReturnValues.)
• ALL_OLD - Returns all of the attributes of the item, as they appeared before the UpdateItem operation.
• UPDATED_OLD - Returns only the updated attributes, as they appeared before the UpdateItem operation.
• ALL_NEW - Returns all of the attributes of the item, as they appear after the UpdateItem operation.
• UPDATED_NEW - Returns only the updated attributes, as they appear after the UpdateItem operation.

There is no additional cost associated with requesting a return value aside from the small network and processing overhead of receiving a larger response. No read capacity units are consumed.

The values returned are strongly consistent.

An expression that defines one or more attributes to be updated, the action to be performed on them, and new values for them.

The following action values are available for UpdateExpression.

• SET - Adds one or more attributes and values to an item. If any of these attributes already exist, they are replaced by the new values. You can also use SET to add or subtract from an attribute that is of type Number. For example: SET myNum = myNum + :val

  SET supports the following functions:

  • if_not_exists (path, operand) - if the item does not contain an attribute at the specified path, then if_not_exists evaluates to operand; otherwise, it evaluates to path. You can use this function to avoid overwriting an attribute that may already be present in the item.
  • list_append (operand, operand) - evaluates to a list with a new element added to it. You can append the new element to the start or the end of the list by reversing the order of the operands.

  These function names are case-sensitive.

• REMOVE - Removes one or more attributes from an item.

• ADD - Adds the specified value to the item, if the attribute does not already exist. If the attribute does exist, then the behavior of ADD depends on the data type of the attribute:

  • If the existing attribute is a number, and if Value is also a number, then Value is mathematically added to the existing attribute. If Value is a negative number, then it is subtracted from the existing attribute.

    If you use ADD to increment or decrement a number value for an item that doesn't exist before the update, DynamoDB uses 0 as the initial value.

    Similarly, if you use ADD for an existing item to increment or decrement an attribute value that doesn't exist before the update, DynamoDB uses 0 as the initial value. For example, suppose that the item you want to update doesn't have an attribute named itemcount, but you decide to ADD the number 3 to this attribute anyway. DynamoDB will create the itemcount attribute, set its initial value to 0, and finally add 3 to it. The result will be a new itemcount attribute in the item, with a value of 3.

  • If the existing data type is a set and if Value is also a set, then Value is added to the existing set. For example, if the attribute value is the set [1,2], and the ADD action specified [3], then the final attribute value is [1,2,3]. An error occurs if an ADD action is specified for a set attribute and the attribute type specified does not match the existing set type.

    Both sets must have the same primitive data type. For example, if the existing data type is a set of strings, the Value must also be a set of strings.

  The ADD action only supports Number and set data types. In addition, ADD can only be used on top-level attributes, not nested attributes.

• DELETE - Deletes an element from a set.

  If a set of values is specified, then those values are subtracted from the old set. For example, if the attribute value was the set [a,b,c] and the DELETE action specifies [a,c], then the final attribute value is [b]. Specifying an empty set is an error.

  The DELETE action only supports set data types. In addition, DELETE can only be used on top-level attributes, not nested attributes.

You can have many actions in a single expression, such as the following: SET a=:value1, b=:value2 DELETE :value3, :value4, :value5

For more information on update expressions, see Modifying Items and Attributes in the Amazon DynamoDB Developer Guide.

One or more values that can be substituted in an expression.

Use the : (colon) character in an expression to dereference an attribute value. For example, suppose that you wanted to check whether the value of the ProductStatus attribute was one of the following:

Available | Backordered | Discontinued

You would first need to specify ExpressionAttributeValues as follows:

{ ":avail":{"S":"Available"}, ":back":{"S":"Backordered"}, ":disc":{"S":"Discontinued"} }

You could then use these values in an expression, such as this:

ProductStatus IN (:avail, :back, :disc)

For more information on expression attribute values, see Condition Expressions in the Amazon DynamoDB Developer Guide.

This is a legacy parameter. Use UpdateExpression instead. For more information, see AttributeUpdates in the Amazon DynamoDB Developer Guide.

Undocumented member.

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.

A condition that must be satisfied in order for a conditional update to succeed.

An expression can contain any of the following:

• Functions: attribute_exists | attribute_not_exists | attribute_type | contains | begins_with | size

  These function names are case-sensitive.

• Comparison operators: = | <> | < | > | <= | >= | BETWEEN | IN
• Logical operators: AND | OR | NOT

For more information about condition expressions, see Specifying Conditions in the Amazon DynamoDB Developer Guide.

This is a legacy parameter. Use ConditionExpression instead. For more information, see ConditionalOperator in the Amazon DynamoDB Developer Guide.

This is a legacy parameter. Use ConditionExpression instead. For more information, see Expected in the Amazon DynamoDB Developer Guide.

The name of the table containing the item to update.

The primary key of the item to be updated. Each element consists of an attribute name and a value for that attribute.

For the primary key, you must provide all of the 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.

Information about item collections, if any, that were affected by the UpdateItem operation. ItemCollectionMetrics is only returned if the ReturnItemCollectionMetrics parameter was specified. If the table does not have any local secondary indexes, this information is not returned in the response.

Each ItemCollectionMetrics element consists of:

• ItemCollectionKey - The partition key value of the item collection. This is the same as the partition key value of the item itself.

• SizeEstimateRangeGB - An estimate of item collection size, in gigabytes. This value 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 that 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.

The capacity units consumed by the UpdateItem operation. The data returned includes the total provisioned throughput consumed, along with statistics for the table and any indexes involved in the operation. ConsumedCapacity is only returned if the ReturnConsumedCapacity parameter was specified. For more information, see Provisioned Throughput in the Amazon DynamoDB Developer Guide.

A map of attribute values as they appear before or after the UpdateItem operation, as determined by the ReturnValues parameter.

The Attributes map is only present if ReturnValues was specified as something other than NONE in the request. Each element represents one attribute.

The response's http status code.

The name of the DynamoDB table.

The ARN for a Kinesis data stream.

The current status of the replication.

The ARN for the specific Kinesis data stream.

The name of the table being modified.

Lists the global tables in a specific Region.

The first global table name that this operation will evaluate.

The maximum number of table names to return, if the parameter is not specified DynamoDB defaults to 100.

If the number of global tables DynamoDB finds reaches this limit, it stops the operation and returns the table names collected up to that point, with a table name in the LastEvaluatedGlobalTableName to apply in a subsequent operation to the ExclusiveStartGlobalTableName parameter.

Last evaluated global table name.

List of global table names.

The response's http status code.

The global table name.

A list of Regions that should be added or removed from the global table.

Contains the details of the global table.

The response's http status code.

The name of the table to delete.

Represents the properties of a table.

The response's http status code.

An array of attributes that describe the key schema for the table and indexes. If you are adding a new global secondary index to the table, AttributeDefinitions must include the key element(s) of the new index.

The new provisioned throughput settings for the specified table or index.

The new server-side encryption settings for the specified table.

A list of replica update actions (create, delete, or update) for the table.

This property only applies to Version 2019.11.21 of global tables.

An array of one or more global secondary indexes for the table. For each index in the array, you can request one action:

• Create - add a new global secondary index to the table.
• Update - modify the provisioned throughput settings of an existing global secondary index.
• Delete - remove a global secondary index from the table.

You can create or delete only one global secondary index per UpdateTable operation.

For more information, see Managing Global Secondary Indexes in the Amazon DynamoDB Developer Guide.

Controls how you are charged for read and write throughput and how you manage capacity. When switching from pay-per-request to provisioned capacity, initial provisioned capacity values must be set. The initial provisioned capacity values are estimated based on the consumed read and write capacity of your table and global secondary indexes over the past 30 minutes.

• PROVISIONED - We recommend using PROVISIONED for predictable workloads. PROVISIONED sets the billing mode to Provisioned Mode.
• PAY_PER_REQUEST - We recommend using PAY_PER_REQUEST for unpredictable workloads. PAY_PER_REQUEST sets the billing mode to On-Demand Mode.

Represents the DynamoDB Streams configuration for the table.

You receive a ResourceInUseException if you try to enable a stream on a table that already has a stream, or if you try to disable a stream on a table that doesn't have a stream.

The name of the table to be updated.

Represents the properties of the table.

The response's http status code.

Undocumented member.

A map of one or more table names and, for each table, a map that describes one or more items to retrieve from that table. Each table name can be used only once per BatchGetItem request.

Each element in the map of items to retrieve consists of the following:

• ConsistentRead - If true, a strongly consistent read is used; if false (the default), an eventually consistent read is used.

• ExpressionAttributeNames - One or more substitution tokens for attribute names in the ProjectionExpression parameter. The following are some use cases for using ExpressionAttributeNames:

  • To access an attribute whose name conflicts with a DynamoDB reserved word.
  • To create a placeholder for repeating occurrences of an attribute name in an expression.
  • To prevent special characters in an attribute name from being misinterpreted in an expression.

  Use the # character in an expression to dereference an attribute name. For example, consider the following attribute name:

  • Percentile

  The name of this attribute conflicts with a reserved word, so it cannot be used directly in an expression. (For the complete list of reserved words, see Reserved Words in the Amazon DynamoDB Developer Guide). To work around this, you could specify the following for ExpressionAttributeNames:

  • {"#P":"Percentile"}

  You could then use this substitution in an expression, as in this example:

  • #P = :val

  Tokens that begin with the : character are /expression attribute values/, which are placeholders for the actual value at runtime.

  For more information about expression attribute names, see Accessing Item Attributes in the Amazon DynamoDB Developer Guide.

• Keys - An array of primary key attribute values that define specific items in the table. For each primary key, you must provide all of the key attributes. For example, with a simple primary key, you only need to provide the partition key value. For a composite key, you must provide both the partition key value and the sort key value.

• ProjectionExpression - A string that identifies one or more attributes to retrieve from the table. These attributes can include scalars, sets, or elements of a JSON document. The attributes in the expression must be separated by commas.

  If no attribute names are specified, then all attributes are returned. If any of the requested attributes are not found, they do not appear in the result.

  For more information, see Accessing Item Attributes in the Amazon DynamoDB Developer Guide.

• AttributesToGet - This is a legacy parameter. Use ProjectionExpression instead. For more information, see AttributesToGet in the Amazon DynamoDB Developer Guide.

A map of tables and their respective keys that were not processed with the current response. The UnprocessedKeys value is in the same form as RequestItems, so the value can be provided directly to a subsequent BatchGetItem operation. For more information, see RequestItems in the Request Parameters section.

Each element consists of:

• Keys - An array of primary key attribute values that define specific items in the table.
• ProjectionExpression - One or more attributes to be retrieved from the table or index. By default, all attributes are returned. If a requested attribute is not found, it does not appear in the result.
• ConsistentRead - The consistency of a read operation. If set to true, then a strongly consistent read is used; otherwise, an eventually consistent read is used.

If there are no unprocessed keys remaining, the response contains an empty UnprocessedKeys map.

A map of table name to a list of items. Each object in Responses consists of a table name, along with a map of attribute data consisting of the data type and attribute value.

The read capacity units consumed by the entire BatchGetItem operation.

Each element consists of:

• TableName - The table that consumed the provisioned throughput.
• CapacityUnits - The total number of capacity units consumed.

The response's http status code.

Only backups created before this time are listed. TimeRangeUpperBound is exclusive.

Only backups created after this time are listed. TimeRangeLowerBound is inclusive.

Maximum number of backups to return at once.

LastEvaluatedBackupArn is the Amazon Resource Name (ARN) of the backup last evaluated when the current page of results was returned, inclusive of the current page of results. This value may be specified as the ExclusiveStartBackupArn of a new ListBackups operation in order to fetch the next page of results.

The backups from the table specified by BackupType are listed.

Where BackupType can be:

• USER - On-demand backup created by you.
• SYSTEM - On-demand backup automatically created by DynamoDB.
• ALL - All types of on-demand backups (USER and SYSTEM).

The backups from the table specified by TableName are listed.

List of BackupSummary objects.

The ARN of the backup last evaluated when the current page of results was returned, inclusive of the current page of results. This value may be specified as the ExclusiveStartBackupArn of a new ListBackups operation in order to fetch the next page of results.

If LastEvaluatedBackupArn is empty, then the last page of results has been processed and there are no more results to be retrieved.

If LastEvaluatedBackupArn is not empty, this may or may not indicate that there is more data to be returned. All results are guaranteed to have been returned if and only if no value for LastEvaluatedBackupArn is returned.

The response's http status code.

The ARN associated with the backup.

Contains the description of the backup created for the table.

The response's http status code.

The name of the table.

Specified name for the backup.

Contains the details of the backup created for the table.

The response's http status code.

Represents the auto scaling settings of replicas of the table that will be modified.

Undocumented member.

Represents the auto scaling settings of the global secondary indexes of the replica to be updated.

The name of the global table to be updated.

Returns information about the auto scaling settings of a table with replicas.

The response's http status code.

The name of the global table to describe.

The Region-specific settings for the global table.

The name of the global table.

The response's http status code.

An optional string that, if supplied, must be copied from the output of a previous call to ListTagOfResource. When provided in this manner, this API fetches the next page of results.

The Amazon DynamoDB resource with tags to be listed. This value is an Amazon Resource Name (ARN).

If this value is returned, there are additional results to be displayed. To retrieve them, call ListTagsOfResource again, with NextToken set to this value.

The tags currently associated with the Amazon DynamoDB resource.

The response's http status code.

The name of the global table.

Contains the details of the global table.

The response's http status code.

The name of the table to describe.

The properties of the table.

The response's http status code.

The maximum write capacity units that your account allows you to provision for a new table that you are creating in this Region, including the write capacity units provisioned for its global secondary indexes (GSIs).

The maximum read capacity units that your account allows you to provision for a new table that you are creating in this Region, including the read capacity units provisioned for its global secondary indexes (GSIs).

The maximum total write capacity units that your account allows you to provision across all of your tables in this Region.

The maximum total read capacity units that your account allows you to provision across all of your tables in this Region.

The response's http status code.

Set this value to get remaining results, if NextToken was returned in the statement response.

The list of PartiQL statements representing the transaction to run.

The response to a PartiQL transaction.

The response's http status code.

A string that identifies one or more attributes to retrieve from the table. These attributes can include scalars, sets, or elements of a JSON document. The attributes in the expression must be separated by commas.

If no attribute names are specified, then all attributes are returned. If any of the requested attributes are not found, they do not appear in the result.

For more information, see Specifying Item Attributes in the Amazon DynamoDB Developer Guide.

This is a legacy parameter. Use ProjectionExpression instead. For more information, see AttributesToGet in the Amazon DynamoDB Developer Guide.

One or more substitution tokens for attribute names in an expression. The following are some use cases for using ExpressionAttributeNames:

• To access an attribute whose name conflicts with a DynamoDB reserved word.
• To create a placeholder for repeating occurrences of an attribute name in an expression.
• To prevent special characters in an attribute name from being misinterpreted in an expression.

Use the # character in an expression to dereference an attribute name. For example, consider the following attribute name:

• Percentile

The name of this attribute conflicts with a reserved word, so it cannot be used directly in an expression. (For the complete list of reserved words, see Reserved Words in the Amazon DynamoDB Developer Guide). To work around this, you could specify the following for ExpressionAttributeNames:

• {"#P":"Percentile"}

You could then use this substitution in an expression, as in this example:

• #P = :val

Tokens that begin with the : character are /expression attribute values/, which are placeholders for the actual value at runtime.

For more information on expression attribute names, see Specifying Item Attributes in the Amazon DynamoDB Developer Guide.

Determines the read consistency model: If set to true, then the operation uses strongly consistent reads; otherwise, the operation uses eventually consistent reads.

Undocumented member.

The name of the table containing the requested item.

A map of attribute names to AttributeValue objects, representing the primary key of the item to retrieve.

For the primary key, you must provide all of the 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.

The capacity units consumed by the GetItem operation. The data returned includes the total provisioned throughput consumed, along with statistics for the table and any indexes involved in the operation. ConsumedCapacity is only returned if the ReturnConsumedCapacity parameter was specified. For more information, see Read/Write Capacity Mode in the Amazon DynamoDB Developer Guide.

A map of attribute names to AttributeValue objects, as specified by ProjectionExpression.

The response's http status code.

The Amazon Resource Name (ARN) associated with the backup.

Contains the description of the backup created for the table.

The response's http status code.

The list of PartiQL statements representing the batch to run.

The response to each PartiQL statement in the batch.

The response's http status code.

The name of the table.

Represents the auto scaling properties of the table.

The response's http status code.

Auto scaling settings for managing provisioned write capacity for the global table.

The billing mode of the global table. If GlobalTableBillingMode is not specified, the global table defaults to PROVISIONED capacity billing mode.

• PROVISIONED - We recommend using PROVISIONED for predictable workloads. PROVISIONED sets the billing mode to Provisioned Mode.
• PAY_PER_REQUEST - We recommend using PAY_PER_REQUEST for unpredictable workloads. PAY_PER_REQUEST sets the billing mode to On-Demand Mode.

The maximum number of writes consumed per second before DynamoDB returns a ThrottlingException.

Represents the settings for a global table in a Region that will be modified.

Represents the settings of a global secondary index for a global table that will be modified.

The name of the global table

The Region-specific settings for the global table.

The name of the global table.

The response's http status code.

The name of the DynamoDB table.

The ARN for a Kinesis data stream.

The current status of the replication.

The ARN for the specific Kinesis data stream.

The name of the table being modified.

A value of TOTAL causes consumed capacity information to be returned, and a value of NONE prevents that information from being returned. No other value is valid.

An ordered array of up to 25 TransactGetItem objects, each of which contains a Get structure.

An ordered array of up to 25 ItemResponse objects, each of which corresponds to the TransactGetItem object in the same position in the TransactItems array. Each ItemResponse object contains a Map of the name-value pairs that are the projected attributes of the requested item.

If a requested item could not be retrieved, the corresponding ItemResponse object is Null, or if the requested item has no projected attributes, the corresponding ItemResponse object is an empty Map.

If the ReturnConsumedCapacity value was TOTAL, this is an array of ConsumedCapacity objects, one for each table addressed by TransactGetItem objects in the TransactItems parameter. These ConsumedCapacity objects report the read-capacity units consumed by the TransactGetItems call in that table.

The response's http status code.

A token to for the desired page, if there is one.

Maximum number of results to return per page.

The name of the table.

A list of ContributorInsightsSummary.

A token to go to the next page if there is one.

The response's http status code.

Undocumented member.

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.

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 are 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.

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.

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.

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.

The response's http status code.

The ID of the AWS account that owns the bucket the export will be stored in.

The format for the exported data. Valid values for ExportFormat are DYNAMODB_JSON or ION.

The ID of the AWS KMS managed key used to encrypt the S3 bucket where export data will be stored (if applicable).

Providing a ClientToken makes the call to ExportTableToPointInTimeInput idempotent, meaning that multiple identical calls have the same effect as one single call.

A client token is valid for 8 hours after the first request that uses it is completed. After 8 hours, any request with the same client token is treated as a new request. Do not resubmit the same request with the same client token for more than 8 hours, or the result might not be idempotent.

If you submit a request with the same client token but a change in other parameters within the 8-hour idempotency window, DynamoDB returns an IdempotentParameterMismatch exception.

Time in the past from which to export table data. The table export will be a snapshot of the table's state at this point in time.

Type of encryption used on the bucket where export data will be stored. Valid values for S3SseAlgorithm are:

• AES256 - server-side encryption with Amazon S3 managed keys
• KMS - server-side encryption with AWS KMS managed keys

The Amazon S3 bucket prefix to use as the file name and path of the exported snapshot.

The Amazon Resource Name (ARN) associated with the table to export.

The name of the Amazon S3 bucket to export the snapshot to.

Contains a description of the table export.

The response's http status code.

Undocumented member.

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 and are returned in the response. If set to NONE (the default), no statistics are returned.

Providing a ClientRequestToken makes the call to TransactWriteItems idempotent, meaning that multiple identical calls have the same effect as one single call.

Although multiple identical calls using the same client request token produce the same result on the server (no side effects), the responses to the calls might not be the same. If the ReturnConsumedCapacity> parameter is set, then the initial TransactWriteItems call returns the amount of write capacity units consumed in making the changes. Subsequent TransactWriteItems calls with the same client token return the number of read capacity units consumed in reading the item.

A client request token is valid for 10 minutes after the first request that uses it is completed. After 10 minutes, any request with the same client token is treated as a new request. Do not resubmit the same request with the same client token for more than 10 minutes, or the result might not be idempotent.

If you submit a request with the same client token but a change in other parameters within the 10-minute idempotency window, DynamoDB returns an IdempotentParameterMismatch exception.

An ordered array of up to 25 TransactWriteItem objects, each of which contains a ConditionCheck, Put, Update, or Delete object. These can operate on items in different tables, but the tables must reside in the same AWS account and Region, and no two of them can operate on the same item.

A list of tables that were processed by TransactWriteItems and, for each table, information about any item collections that were affected by individual UpdateItem, PutItem, or DeleteItem operations.

The capacity units consumed by the entire TransactWriteItems operation. The values of the list are ordered according to the ordering of the TransactItems request parameter.

The response's http status code.

The first table name that this operation will evaluate. Use the value that was returned for LastEvaluatedTableName in a previous operation, so that you can obtain the next page of results.

A maximum number of table names to return. If this parameter is not specified, the limit is 100.

The name of the last table in the current page of results. Use this value as the ExclusiveStartTableName in a new request to obtain the next page of results, until all the table names are returned.

If you do not receive a LastEvaluatedTableName value in the response, this means that there are no more table names to be retrieved.

The names of the tables associated with the current account at the current endpoint. The maximum size of this array is 100.

If LastEvaluatedTableName also appears in the output, you can use this value as the ExclusiveStartTableName parameter in a subsequent ListTables request and obtain the next page of results.

The response's http status code.

A string that identifies one or more attributes to retrieve from the specified table or index. These attributes can include scalars, sets, or elements of a JSON document. The attributes in the expression must be separated by commas.

If no attribute names are specified, then all attributes will be returned. If any of the requested attributes are not found, they will not appear in the result.

For more information, see Specifying Item Attributes in the Amazon DynamoDB Developer Guide.

This is a legacy parameter. Use FilterExpression instead. For more information, see ScanFilter in the Amazon DynamoDB Developer Guide.

This is a legacy parameter. Use ProjectionExpression instead. For more information, see AttributesToGet in the Amazon DynamoDB Developer Guide.

For a parallel Scan request, TotalSegments represents the total number of segments into which the Scan operation will be divided. The value of TotalSegments corresponds to the number of application workers that will perform the parallel scan. For example, if you want to use four application threads to scan a table or an index, specify a TotalSegments value of 4.

The value for TotalSegments must be greater than or equal to 1, and less than or equal to 1000000. If you specify a TotalSegments value of 1, the Scan operation will be sequential rather than parallel.

If you specify TotalSegments, you must also specify Segment.

One or more substitution tokens for attribute names in an expression. The following are some use cases for using ExpressionAttributeNames:

• To access an attribute whose name conflicts with a DynamoDB reserved word.
• To create a placeholder for repeating occurrences of an attribute name in an expression.
• To prevent special characters in an attribute name from being misinterpreted in an expression.

Use the # character in an expression to dereference an attribute name. For example, consider the following attribute name:

• Percentile

The name of this attribute conflicts with a reserved word, so it cannot be used directly in an expression. (For the complete list of reserved words, see Reserved Words in the Amazon DynamoDB Developer Guide). To work around this, you could specify the following for ExpressionAttributeNames:

• {"#P":"Percentile"}

You could then use this substitution in an expression, as in this example:

• #P = :val

Tokens that begin with the : character are /expression attribute values/, which are placeholders for the actual value at runtime.

For more information on expression attribute names, see Specifying Item Attributes in the Amazon DynamoDB Developer Guide.

A string that contains conditions that DynamoDB applies after the Scan operation, but before the data is returned to you. Items that do not satisfy the FilterExpression criteria are not returned.

A FilterExpression is applied after the items have already been read; the process of filtering does not consume any additional read capacity units.

For more information, see Filter Expressions in the Amazon DynamoDB Developer Guide.

A Boolean value that determines the read consistency model during the scan:

• If ConsistentRead is false, then the data returned from Scan might not contain the results from other recently completed write operations (PutItem, UpdateItem, or DeleteItem).
• If ConsistentRead is true, then all of the write operations that completed before the Scan began are guaranteed to be contained in the Scan response.

The default setting for ConsistentRead is false.

The ConsistentRead parameter is not supported on global secondary indexes. If you scan a global secondary index with ConsistentRead set to true, you will receive a ValidationException.

One or more values that can be substituted in an expression.

Use the : (colon) character in an expression to dereference an attribute value. For example, suppose that you wanted to check whether the value of the ProductStatus attribute was one of the following:

Available | Backordered | Discontinued

You would first need to specify ExpressionAttributeValues as follows:

{ ":avail":{"S":"Available"}, ":back":{"S":"Backordered"}, ":disc":{"S":"Discontinued"} }

You could then use these values in an expression, such as this:

ProductStatus IN (:avail, :back, :disc)

For more information on expression attribute values, see Condition Expressions in the Amazon DynamoDB Developer Guide.

Undocumented member.

The maximum number of items to evaluate (not necessarily the number of matching items). If DynamoDB processes the number of items up to the limit while processing the results, it stops the operation and returns the matching values up to that point, and a key in LastEvaluatedKey to apply in a subsequent operation, so that you can pick up where you left off. Also, if the processed dataset size exceeds 1 MB before DynamoDB reaches this limit, it stops the operation and returns the matching values up to the limit, and a key in LastEvaluatedKey to apply in a subsequent operation to continue the operation. For more information, see Working with Queries in the Amazon DynamoDB Developer Guide.

The attributes to be returned in the result. You can retrieve all item attributes, specific item attributes, the count of matching items, or in the case of an index, some or all of the attributes projected into the index.

• ALL_ATTRIBUTES - Returns all of the item attributes from the specified table or index. If you query a local secondary index, then for each matching item in the index, DynamoDB fetches the entire item from the parent table. If the index is configured to project all item attributes, then all of the data can be obtained from the local secondary index, and no fetching is required.
• ALL_PROJECTED_ATTRIBUTES - Allowed only when querying an index. Retrieves all attributes that have been projected into the index. If the index is configured to project all attributes, this return value is equivalent to specifying ALL_ATTRIBUTES.
• COUNT - Returns the number of matching items, rather than the matching items themselves.

• SPECIFIC_ATTRIBUTES - Returns only the attributes listed in AttributesToGet. This return value is equivalent to specifying AttributesToGet without specifying any value for Select.

  If you query or scan a local secondary index and request only attributes that are projected into that index, the operation reads only the index and not the table. If any of the requested attributes are not projected into the local secondary index, DynamoDB fetches each of these attributes from the parent table. This extra fetching incurs additional throughput cost and latency.

  If you query or scan a global secondary index, you can only request attributes that are projected into the index. Global secondary index queries cannot fetch attributes from the parent table.

If neither Select nor AttributesToGet are specified, DynamoDB defaults to ALL_ATTRIBUTES when accessing a table, and ALL_PROJECTED_ATTRIBUTES when accessing an index. You cannot use both Select and AttributesToGet together in a single request, unless the value for Select is SPECIFIC_ATTRIBUTES. (This usage is equivalent to specifying AttributesToGet without any value for Select.)

If you use the ProjectionExpression parameter, then the value for Select can only be SPECIFIC_ATTRIBUTES. Any other value for Select will return an error.

For a parallel Scan request, Segment identifies an individual segment to be scanned by an application worker.

Segment IDs are zero-based, so the first segment is always 0. For example, if you want to use four application threads to scan a table or an index, then the first thread specifies a Segment value of 0, the second thread specifies 1, and so on.

The value of LastEvaluatedKey returned from a parallel Scan request must be used as ExclusiveStartKey with the same segment ID in a subsequent Scan operation.

The value for Segment must be greater than or equal to 0, and less than the value provided for TotalSegments.

If you provide Segment, you must also provide TotalSegments.

This is a legacy parameter. Use FilterExpression instead. For more information, see ConditionalOperator in the Amazon DynamoDB Developer Guide.

The primary key of the first item that this operation will evaluate. Use the value that was returned for LastEvaluatedKey in the previous operation.

The data type for ExclusiveStartKey must be String, Number or Binary. No set data types are allowed.

In a parallel scan, a Scan request that includes ExclusiveStartKey must specify the same segment whose previous Scan returned the corresponding value of LastEvaluatedKey.

The name of a secondary index to scan. This index can be any local secondary index or global secondary index. Note that if you use the IndexName parameter, you must also provide TableName.

The name of the table containing the requested items; or, if you provide IndexName, the name of the table to which that index belongs.

The primary key of the item where the operation stopped, inclusive of the previous result set. Use this value to start a new operation, excluding this value in the new request.

If LastEvaluatedKey is empty, then the "last page" of results has been processed and there is no more data to be retrieved.

If LastEvaluatedKey is not empty, it does not necessarily mean that there is more data in the result set. The only way to know when you have reached the end of the result set is when LastEvaluatedKey is empty.

The number of items in the response.

If you set ScanFilter in the request, then Count is the number of items returned after the filter was applied, and ScannedCount is the number of matching items before the filter was applied.

If you did not use a filter in the request, then Count is the same as ScannedCount.

The number of items evaluated, before any ScanFilter is applied. A high ScannedCount value with few, or no, Count results indicates an inefficient Scan operation. For more information, see Count and ScannedCount in the Amazon DynamoDB Developer Guide.

If you did not use a filter in the request, then ScannedCount is the same as Count.

An array of item attributes that match the scan criteria. Each element in this array consists of an attribute name and the value for that attribute.

The capacity units consumed by the Scan operation. The data returned includes the total provisioned throughput consumed, along with statistics for the table and any indexes involved in the operation. ConsumedCapacity is only returned if the ReturnConsumedCapacity parameter was specified. For more information, see Provisioned Throughput in the Amazon DynamoDB Developer Guide.

The response's http status code.

The global secondary index name, if applicable.

The name of the table.

Represents the contributor insights action.

The status of contributor insights

The name of the table.

The name of the global secondary index, if applicable.

The response's http status code.

The consistency of a read operation. If set to true, then a strongly consistent read is used; otherwise, an eventually consistent read is used.

Set this value to get remaining results, if NextToken was returned in the statement response.

The parameters for the PartiQL statement, if any.