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Class ScanCommand

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.

example

Use a bare-bones client and the command you need to make an API call.

import { DynamoDBClient, ScanCommand } from "@aws-sdk/client-dynamodb"; // ES Modules import
// const { DynamoDBClient, ScanCommand } = require("@aws-sdk/client-dynamodb"); // CommonJS import
const client = new DynamoDBClient(config);
const command = new ScanCommand(input);
const response = await client.send(command);
see

ScanCommandInput for command's input shape.

see

ScanCommandOutput for command's response shape.

see

config for DynamoDBClient's config shape.

Hierarchy

Implements

Index

Constructors

Properties

Constructors

constructor

Properties

Readonly input

input: ScanCommandInput

Readonly middlewareStack

middlewareStack: IMiddlewareStack<ScanCommandInput, ScanCommandOutput>