# Dataset
<a name="API_Dataset"></a>

A collection of data for an identity pool. An identity pool can have multiple datasets. A dataset is per identity and can be general or associated with a particular entity in an application (like a saved game). Datasets are automatically created if they don't exist. Data is synced by dataset, and a dataset can hold up to 1MB of key-value pairs.

## Contents
<a name="API_Dataset_Contents"></a>

 ** CreationDate **   <a name="Cognito-Type-Dataset-CreationDate"></a>
Date on which the dataset was created.  
Type: Timestamp  
Required: No

 ** DatasetName **   <a name="Cognito-Type-Dataset-DatasetName"></a>
A string of up to 128 characters. Allowed characters are a-z, A-Z, 0-9, '\$1' (underscore), '-' (dash), and '.' (dot).  
Type: String  
Length Constraints: Minimum length of 1. Maximum length of 128.  
Pattern: `[a-zA-Z0-9_.:-]+`   
Required: No

 ** DataStorage **   <a name="Cognito-Type-Dataset-DataStorage"></a>
Total size in bytes of the records in this dataset.  
Type: Long  
Required: No

 ** IdentityId **   <a name="Cognito-Type-Dataset-IdentityId"></a>
A name-spaced GUID (for example, us-east-1:23EC4050-6AEA-7089-A2DD-08002EXAMPLE) created by Amazon Cognito. GUID generation is unique within a region.  
Type: String  
Length Constraints: Minimum length of 1. Maximum length of 55.  
Pattern: `[\w-]+:[0-9a-f-]+`   
Required: No

 ** LastModifiedBy **   <a name="Cognito-Type-Dataset-LastModifiedBy"></a>
The device that made the last change to this dataset.  
Type: String  
Required: No

 ** LastModifiedDate **   <a name="Cognito-Type-Dataset-LastModifiedDate"></a>
Date when the dataset was last modified.  
Type: Timestamp  
Required: No

 ** NumRecords **   <a name="Cognito-Type-Dataset-NumRecords"></a>
Number of records in this dataset.  
Type: Long  
Required: No

## See Also
<a name="API_Dataset_SeeAlso"></a>

For more information about using this API in one of the language-specific AWS SDKs, see the following:
+  [AWS SDK for C\$1\$1](https://docs.aws.amazon.com/goto/SdkForCpp/cognito-sync-2014-06-30/Dataset) 
+  [AWS SDK for Java V2](https://docs.aws.amazon.com/goto/SdkForJavaV2/cognito-sync-2014-06-30/Dataset) 
+  [AWS SDK for Ruby V3](https://docs.aws.amazon.com/goto/SdkForRubyV3/cognito-sync-2014-06-30/Dataset)