AWS Tools for Windows PowerShell
Command Reference

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Synopsis

Calls the Amazon DynamoDB Scan API operation.

Syntax

Invoke-DDBScan
-TableName <String>
-AttributesToGet <String[]>
-ConditionalOperator <ConditionalOperator>
-ConsistentRead <Boolean>
-ExpressionAttributeName <Hashtable>
-ExpressionAttributeValue <Hashtable>
-FilterExpression <String>
-IndexName <String>
-IsLimitSet <Boolean>
-IsSegmentSet <Boolean>
-IsTotalSegmentsSet <Boolean>
-ProjectionExpression <String>
-ReturnConsumedCapacity <ReturnConsumedCapacity>
-ScanFilter <Hashtable>
-Segment <Int32>
-SelectItem <Select>
-TotalSegment <Int32>
-ExclusiveStartKey <Hashtable>
-Limit <Int32>
-Select <String>
-PassThru <SwitchParameter>
-Force <SwitchParameter>
-NoAutoIteration <SwitchParameter>
-ClientConfig <AmazonDynamoDBConfig>

Description

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 size of scanned items exceeds the maximum dataset size limit of 1 MB, the scan completes and results are returned to the user. The LastEvaluatedKey value is also returned and the requestor can use the LastEvaluatedKey to continue the scan in a subsequent operation. Each scan response also includes number of items that were scanned (ScannedCount) as part of the request. If using a FilterExpression, a scan result can result in no items meeting the criteria and the Count will result in zero. If you did not use a FilterExpression in the scan request, then Count is the same as ScannedCount. Count and ScannedCount only return the count of items specific to a single scan request and, unless the table is less than 1MB, do not represent the total number of items in the table. A single Scan operation first reads up to the maximum number of items set (if using the Limit parameter) or a maximum of 1 MB of data and then applies any filtering to the results if a FilterExpression is provided. If LastEvaluatedKey is present in the response, pagination is required to complete the full table scan. 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. By default, a Scan uses eventually consistent reads when accessing the items in a table. Therefore, the results from an eventually consistent Scan may not include the latest item changes at the time the scan iterates through each item in the table. If you require a strongly consistent read of each item as the scan iterates through the items in the table, you can set the ConsistentRead parameter to true. Strong consistency only relates to the consistency of the read at the item level. DynamoDB does not provide snapshot isolation for a scan operation when the ConsistentRead parameter is set to true. Thus, a DynamoDB scan operation does not guarantee that all reads in a scan see a consistent snapshot of the table when the scan operation was requested.

This cmdlet automatically pages all available results to the pipeline - parameters related to iteration are only needed if you want to manually control the paginated output. To disable autopagination, use -NoAutoIteration.

Parameters

-AttributesToGet <String[]>
This is a legacy parameter. Use ProjectionExpression instead. For more information, see AttributesToGet in the Amazon DynamoDB Developer Guide.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
-ClientConfig <AmazonDynamoDBConfig>
Amazon.PowerShell.Cmdlets.DDB.AmazonDynamoDBClientCmdlet.ClientConfig
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
-ConditionalOperator <ConditionalOperator>
This is a legacy parameter. Use FilterExpression instead. For more information, see ConditionalOperator in the Amazon DynamoDB Developer Guide.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
-ConsistentRead <Boolean>
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.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
-ExclusiveStartKey <Hashtable>
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.
Note: This parameter is only used if you are manually controlling output pagination of the service API call.
'ExclusiveStartKey' is only returned by the cmdlet when '-Select *' is specified. In order to manually control output pagination, set '-ExclusiveStartKey' to null for the first call then set the 'ExclusiveStartKey' using the same property output from the previous call for subsequent calls.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
AliasesNextToken
-ExpressionAttributeName <Hashtable>
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.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
AliasesExpressionAttributeNames
-ExpressionAttributeValue <Hashtable>
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 | DiscontinuedYou 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.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
AliasesExpressionAttributeValues
-FilterExpression <String>
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.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
-Force <SwitchParameter>
This parameter overrides confirmation prompts to force the cmdlet to continue its operation. This parameter should always be used with caution.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
-IndexName <String>
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.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
-IsLimitSet <Boolean>
This property is set to true if the property is set; false otherwise. This property can be used to determine if the related property was returned by a service response or if the related property should be sent to the service during a service call.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
-IsSegmentSet <Boolean>
This property is set to true if the property is set; false otherwise. This property can be used to determine if the related property was returned by a service response or if the related property should be sent to the service during a service call.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
-IsTotalSegmentsSet <Boolean>
This property is set to true if the property is set; false otherwise. This property can be used to determine if the related property was returned by a service response or if the related property should be sent to the service during a service call.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
-Limit <Int32>
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.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
-NoAutoIteration <SwitchParameter>
By default the cmdlet will auto-iterate and retrieve all results to the pipeline by performing multiple service calls. If set, the cmdlet will retrieve only the next 'page' of results using the value of ExclusiveStartKey as the start point.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
-PassThru <SwitchParameter>
Changes the cmdlet behavior to return the value passed to the TableName parameter. The -PassThru parameter is deprecated, use -Select '^TableName' instead. This parameter will be removed in a future version.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
-ProjectionExpression <String>
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.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
-ReturnConsumedCapacity <ReturnConsumedCapacity>
The service has not provided documentation for this parameter; please refer to the service's API reference documentation for the latest available information.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
-ScanFilter <Hashtable>
This is a legacy parameter. Use FilterExpression instead. For more information, see ScanFilter in the Amazon DynamoDB Developer Guide.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
-Segment <Int32>
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.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
-Select <String>
Use the -Select parameter to control the cmdlet output. The default value is 'Items'. Specifying -Select '*' will result in the cmdlet returning the whole service response (Amazon.DynamoDBv2.Model.ScanResponse). Specifying the name of a property of type Amazon.DynamoDBv2.Model.ScanResponse will result in that property being returned. Specifying -Select '^ParameterName' will result in the cmdlet returning the selected cmdlet parameter value.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
-SelectItem <Select>
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. Note that this uses the same quantity of read capacity units as getting the items, and is subject to the same item size calculations.
  • SPECIFIC_ATTRIBUTES - Returns only the attributes listed in ProjectionExpression. This return value is equivalent to specifying ProjectionExpression 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 ProjectionExpression 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 ProjectionExpression together in a single request, unless the value for Select is SPECIFIC_ATTRIBUTES. (This usage is equivalent to specifying ProjectionExpression 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.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
-TableName <String>
The name of the table containing the requested items or if you provide IndexName, the name of the table to which that index belongs.You can also provide the Amazon Resource Name (ARN) of the table in this parameter.
Required?True
Position?1
Accept pipeline input?True (ByValue, ByPropertyName)
-TotalSegment <Int32>
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.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
AliasesTotalSegments

Common Credential and Region Parameters

-AccessKey <String>
The AWS access key for the user account. This can be a temporary access key if the corresponding session token is supplied to the -SessionToken parameter.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
AliasesAK
-Credential <AWSCredentials>
An AWSCredentials object instance containing access and secret key information, and optionally a token for session-based credentials.
Required?False
Position?Named
Accept pipeline input?True (ByValue, ByPropertyName)
-EndpointUrl <String>
The endpoint to make the call against.Note: This parameter is primarily for internal AWS use and is not required/should not be specified for normal usage. The cmdlets normally determine which endpoint to call based on the region specified to the -Region parameter or set as default in the shell (via Set-DefaultAWSRegion). Only specify this parameter if you must direct the call to a specific custom endpoint.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
-NetworkCredential <PSCredential>
Used with SAML-based authentication when ProfileName references a SAML role profile. Contains the network credentials to be supplied during authentication with the configured identity provider's endpoint. This parameter is not required if the user's default network identity can or should be used during authentication.
Required?False
Position?Named
Accept pipeline input?True (ByValue, ByPropertyName)
-ProfileLocation <String>
Used to specify the name and location of the ini-format credential file (shared with the AWS CLI and other AWS SDKs)If this optional parameter is omitted this cmdlet will search the encrypted credential file used by the AWS SDK for .NET and AWS Toolkit for Visual Studio first. If the profile is not found then the cmdlet will search in the ini-format credential file at the default location: (user's home directory)\.aws\credentials.If this parameter is specified then this cmdlet will only search the ini-format credential file at the location given.As the current folder can vary in a shell or during script execution it is advised that you use specify a fully qualified path instead of a relative path.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
AliasesAWSProfilesLocation, ProfilesLocation
-ProfileName <String>
The user-defined name of an AWS credentials or SAML-based role profile containing credential information. The profile is expected to be found in the secure credential file shared with the AWS SDK for .NET and AWS Toolkit for Visual Studio. You can also specify the name of a profile stored in the .ini-format credential file used with the AWS CLI and other AWS SDKs.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
AliasesStoredCredentials, AWSProfileName
-Region <Object>
The system name of an AWS region or an AWSRegion instance. This governs the endpoint that will be used when calling service operations. Note that the AWS resources referenced in a call are usually region-specific.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
AliasesRegionToCall
-SecretKey <String>
The AWS secret key for the user account. This can be a temporary secret key if the corresponding session token is supplied to the -SessionToken parameter.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
AliasesSK, SecretAccessKey
-SessionToken <String>
The session token if the access and secret keys are temporary session-based credentials.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
AliasesST

Outputs

System.Collections.Generic.DictionaryAmazon.DynamoDBv2.Model.AttributeValue> or Amazon.DynamoDBv2.Model.ScanResponse
This cmdlet returns a collection of Dictionary<System.String, Amazon.DynamoDBv2.Model.AttributeValue> objects. The service call response (type Amazon.DynamoDBv2.Model.ScanResponse) can be returned by specifying '-Select *'.

Examples

Example 1

Invoke-DDBScan -TableName 'Music' | ConvertFrom-DDBItem

Name                           Value
----                           -----
Genre                          Country
Artist                         No One You Know
Price                          1.94
CriticRating                   9
SongTitle                      Somewhere Down The Road
AlbumTitle                     Somewhat Famous
Genre                          Country
Artist                         No One You Know
Price                          1.98
CriticRating                   8.4
SongTitle                      My Dog Spot
AlbumTitle                     Hey Now
Returns all items in the Music table.

Example 2

$scanFilter = @{
        CriticRating = [Amazon.DynamoDBv2.Model.Condition]@{
            AttributeValueList = @(@{N = '9'})
            ComparisonOperator = 'GE'
        }
    }
    Invoke-DDBScan -TableName 'Music' -ScanFilter $scanFilter | ConvertFrom-DDBItem

Name                           Value
----                           -----
Genre                          Country
Artist                         No One You Know
Price                          1.94
CriticRating                   9
SongTitle                      Somewhere Down The Road
AlbumTitle                     Somewhat Famous
Returns items in the Music table with a CriticRating greater than or equal to nine.
User Guide
Service API Reference
AWS Tools for PowerShell User Guide

Supported Version

AWS Tools for PowerShell: 2.x.y.z