# Item interactions dataset requirements (VIDEO\_ON\_DEMAND domain)
<a name="VIDEO-ON-DEMAND-interactions-dataset"></a>

 An *Item interactions dataset* stores historical and real-time data from interactions between users and items in your VIDEO\_ON\_DEMAND catalog. For more information about the types of data you can store in an interactions dataset, see [Item interaction data](interactions-datasets.md). 

 You must have an Item interactions dataset for all use cases and your schema must have the following fields: 
+ USER\_ID (`string`)
+ ITEM\_ID `string`
+ TIMESTAMP (`long`)
+ EVENT\_TYPE (`string` and depending on [use case](domain-use-cases.md), `Watch` and `Click` event types)

 Your schema can also include the following reserved keywords:
+ EVENT\_VALUE (`float`, `null`)
+ IMPRESSION (`string`, `null`)
+ RECOMMENDATION\_ID (`string`, `null`)

 You are free to add additional fields depending on your use case and your data. As long as the fields aren't listed as required or reserved, and the data types are listed in [Schema data types](how-it-works-dataset-schema.md#personalize-datatypes), the field names and data types are up to you. For an example of the default schema for Item interactions datasets for VIDEO\_ON\_DEMAND domains, see [Default Interactions schema (VIDEO\_ON\_DEMAND domain)](#VIDEO-ON-DEMAND-interactions-schema). 

 Optionally add the reserved keyword EVENT\_VALUE if you have value data for events, such as the percentage of a video watched. Optionally add the reserved keyword IMPRESSION if you want to include explicit and implicit impressions data. For more information about recording impressions data see [Impressions data](interactions-datasets.md#interactions-impressions-data). 

 The maximum total number of optional metadata fields you can add to an Item interactions dataset, combined with total number of *distinct* event types in your Item interaction data, is 10. The metadata fields included in this count are EVENT\_TYPE, EVENT\_VALUE fields along with any custom metadata fields you add to your schema. The maximum number of metadata fields excluding reserved fields, such as IMPRESSION, is 5. Categorical values can have at most 1000 characters. If you have an interaction with a categorical value with more than 1000, your dataset import job will fail. 

For more information on minimum requirements and maximum data limits for an Item interactions dataset for the VIDEO\_ON\_DEMAND domain, see [Service quotas](limits.md#limits-table). For information about general Amazon Personalize schema requirements, such as formatting requirements and available field data types, see [Creating schema JSON files for Amazon Personalize schemas](how-it-works-dataset-schema.md). These requirements apply to all schemas, regardless of domain. 

## Default Interactions schema (VIDEO\_ON\_DEMAND domain)
<a name="VIDEO-ON-DEMAND-interactions-schema"></a>

 The following is the default VIDEO\_ON\_DEMAND domain schema for Item interactions datasets. 

```
{

  "type": "record",
  "name": "Interactions",
  "namespace": "com.amazonaws.personalize.schema",
  "fields": [
      {
          "name": "USER_ID",
          "type": "string"
      },
      {
          "name": "ITEM_ID",
          "type": "string"
      },
      {
          "name": "EVENT_TYPE",
          "type": "string"
      },
      {
          "name": "TIMESTAMP",
          "type": "long"
      }
  ],
  "version": "1.0"
}
```