--- schema_version: "1" id: b98063bd3ca0c1759ef8f8c72fe1ccdcc63cb1be024f9e34f4926d7feca699a0 title: Data Model Object Relationships collection: admin version: current locale: en-us portal_url: https://docs.salesforce.com/admin/current/en-us/data/264-0-0/c360_a_data_model_object_relationships.md canonical_url: https://help.salesforce.com/s/articleView?id=data.c360_a_data_model_object_relationships.htm&release=264.0.0&type=5 source_site: help.salesforce.com content_type: documentation content_hash: c049a351a8adeef84b3f9759624b012f898c8cf755523369ab44286485d67b12 description: A Data 360 data model object (DMO) can have a standard or custom relationship with other DMOs. The relationship can be structured as a one-to-one or many-to-one relationship. You can view the relationships and their statuses on a DMO record’s Relationships tab. products: - Data 360 release: "264" --- # Data Model Object Relationships A Data 360 data model object (DMO) can have a standard or custom relationship with other DMOs. The relationship can be structured as a one-to-one or many-to-one relationship. You can view the relationships and their statuses on a DMO record’s Relationships tab. ## Cardinality of Relationships When you create a relationship, choose the cardinality carefully. Cardinality between two DMOs has implications for segmentation and activation. You can’t change the cardinality after the relationship is created. If you have a relationship between two objects, for example A and B, and object A has multiple records for each record in object B, the relationship chosen is many-to-one. ![Example](https://sf-zdocs-cdn-prod.zoominsoftware.com/tdta-data-data_cloud-264-0-0-production-enus/f3569962-3c9b-4f83-9d0c-b6a574e785da/images/icon_example.png) Example The relationship between the Contact Point Email DMO and the Individual DMO is structured as many-to-one because the Contact Point Email DMO could have one or more records for each Individual DMO record. Similarly, the relationship between a SalesOrder DMO and an Individual DMO is structured as many-to-one because each Individual record could have more than one order record. ## Standard Relationships The Data 360 data model includes several standard relationships. A standard relationship is inactive until the related object fields are mapped. It’s activated when there’s at least one mapping to both fields in the relationship. The relationship is deactivated when a mapping for at least one field in the relationship is removed. You can disable a standard relationship, but you can’t delete it. A standard relationship is visible on the Relationships tab only when it’s activated. ![Example](https://sf-zdocs-cdn-prod.zoominsoftware.com/tdta-data-data_cloud-264-0-0-production-enus/f3569962-3c9b-4f83-9d0c-b6a574e785da/images/icon_example.png) Example The Data 360 data model includes a relationship between Sales Order.Bill To Email in the Sales Order DMO and Contact Point Email.Contact Point Email Id in the Contact Point Email DMO. This relationship is activated and is visible on the Relationships tab when field mappings exist for both fields. ## Custom Relationships Create a custom relationship between DMOs on the Relationships tab. You can also deactivate a custom relationship or delete it. You can reactivate a deactivated relationship at any time. When you delete a relationship, it’s permanently removed. A custom relationship is automatically deleted if the mappings for at least one field in the relationship is removed. ## DMO Relationship Status A pair of DMOs can have one or more relationships between them, but only one relationship is allowed between a given pair of DMO fields. The relationship status between DMO fields can be active or inactive. View the status of a relationship in the Edit Relationships window. ![Different DMO relationship statues such as active, active and cannot be deactivated, and inactive.](https://sf-zdocs-cdn-prod.zoominsoftware.com/tdta-data-data_cloud-264-0-0-production-enus/f3569962-3c9b-4f83-9d0c-b6a574e785da/data_cloud/images/Edit-DMO-Relationships.png) If the relationship status is active and can be deactivated (1), use the toggle switch to modify the state. When the relationship is deactivated, it can’t be used by downstream functional areas, such as segmentation and activation. However, you can’t deactivate relationships that are being used in calculated insights, segmentation, or activation. Some relationships are active but can’t be deactivated (2). You can’t deactivate relationships that are used by the identity resolution process. By default, deactivated relationships (3) aren’t visible and can be seen only when you select **Show inactive relationships**. Use the toggle to activate the relationships. ## DMO Relationship Limits Data 360 limits the number of custom relationships that can be active for each DMO. When the DMO reaches its active relationship limit, you can’t add a custom relationship or activate an inactive relationship. There isn’t a limit on the number of standard and inactive relationships. ![Nest DMOs into multiple levels.](https://sf-zdocs-cdn-prod.zoominsoftware.com/tdta-data-data_cloud-264-0-0-production-enus/f3569962-3c9b-4f83-9d0c-b6a574e785da/data_cloud/images/c360_a_data_model_object_relationships_flat_or_nested.png) The custom relationship limit applies only to direct relationships associated with a DMO, not indirect relationships. To add more custom relationships, organize DMOs into multiple levels and create a nested structure in the data model. For example, if each DMO is limited to 25 custom relationships but you need 30, decide which 5 DMOs to group together. From the parent DMO, create 25 custom relationships. Designate one of the children as a new parent to the five grouped DMOs. ![Image shows the message when DMO relationship limits are reached.](https://sf-zdocs-cdn-prod.zoominsoftware.com/tdta-data-data_cloud-264-0-0-production-enus/f3569962-3c9b-4f83-9d0c-b6a574e785da/data_cloud/images/DMO-guardrails.png) Data 360 checks for relationship limits when a packaged data bundle is deployed to an org. The package installation fails if the relationship limit is reached. Salesforce starter data bundles, such as the CRM starter bundles, only include standard relationships. Installation of starter bundles will not fail because standard relationships are not counted towards DMO relationship limits. #### See Also - [_Salesforce Help_: Data 360 Limits and Guidelines](https://help.salesforce.com/s/articleView?id=data.c360_a_limits_and_guidelines.htm&release=264.0.0&type=5 "Guidelines define best practice recommendations to optimize your adoption of Data 360 for best performance. Limits are boundaries beyond which features are unavailable, performance is throttled, or usage billing charges are applied. Since Data 360 is built to scale, some limits can be adjusted to meet your business needs. Work with your account executive to find a solution that meets your goals.")