ScanRequest

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

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

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

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

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

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

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.

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 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.

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.

Determines the level of detail about either provisioned or on-demand throughput consumption that is returned in the response:

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

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

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.

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

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.