# Data streams, DLOs and DMO mapping

*Marketing Cloud Next Consultant Study Guide · Data Modeling, Identity Resolution & Segmentation · Last updated November 6, 2026 · https://www.certifyforce.com/study-guide/marketing-cloud-next-consultant/data-modeling-identity-resolution-and-segmentation/data-streams-dlos-and-dmo-mapping*

How customer data moves from a data stream into data lake objects and data model objects, which mappings a custom stream must have, what Simple Start leaves for you to do, and how to check each stage of the pipeline.

- Certification: Salesforce Marketing Cloud Next Consultant
- Exam section: Data Modeling, Identity Resolution & Segmentation
- Study guide: https://www.certifyforce.com/study-guide/marketing-cloud-next-consultant

**Official exam objective:**

> Describe data object concepts in Data 360 and how they are used to connect, harmonize, unify, and activate customer data for audience segmentation and content personalization.

## What the exam expects

- Trace customer data through connect, harmonize, unify and activate, and name the object at each stage.
- Decide what a custom data stream must map for identity resolution, segmentation and activation.
- Pick the right key and object for a person's ID, contact details and third-party identifiers.
- Explain what Simple Start creates and the one step it leaves to you.
- Say which Data 360 tabs the Marketing app shows by default and where the others live.
- Troubleshoot a pipeline by validating that data reached each object.

**Key terms.** *Data stream*: the connection that ingests source data. *DLO (data lake object)*: the container for ingested data. *DMO (data model object)*: a harmonized grouping that DLOs map to. *Party*: the attribute on other objects that references Individual.Id. *Hydration*: here, whether records and key field values actually reached an object.

## Key facts

| Fact | Detail | Source |
|---|---|---|
| Segmentation and activation | Use only mapped fields and objects with relationships | [Data Mapping](https://help.salesforce.com/s/articleView?id=data.c360_a_data_mapping.htm&type=5&language=en_US) |
| Automatic mappings | Only for streams deployed through standard data bundles | [Data Mapping Requirements](https://help.salesforce.com/s/articleView?id=data.c360_a_required_data_mappings.htm&type=5&language=en_US) |
| Party attribute | Foreign key to Individual.Id on contact point and Party Identification objects | [Data Mapping Requirements](https://help.salesforce.com/s/articleView?id=data.c360_a_required_data_mappings.htm&type=5&language=en_US) |
| Contact Point Digital Id | Optional for email or phone destinations | [Data Mapping Requirements](https://help.salesforce.com/s/articleView?id=data.c360_a_required_data_mappings.htm&type=5&language=en_US) |
| DLO fields | Can't be deleted | [Data Objects](https://help.salesforce.com/s/articleView?id=data.c360_a_data_lake_objects.htm&type=5&language=en_US) |
| Stream category | Can't be changed after the stream is saved | [Category](https://help.salesforce.com/s/articleView?id=data.c360_a_category.htm&type=5&language=en_US) |
| Simple Start metadata sync | Available only for accounts and contact objects | [Simple Start](https://help.salesforce.com/s/articleView?id=data.c360_a_simple_start.htm&type=5&language=en_US) |
| Activating Simple Start streams | Data Cloud Architect permission set | [Activate Data Stream Sync](https://help.salesforce.com/s/articleView?id=data.c360_a_activate_data_stream_sync_for_data360.htm&type=5&language=en_US) |
| DLO refresh history | Kept for up to 20 days, in hourly windows | [Refresh History](https://help.salesforce.com/s/articleView?id=data.c360_a_datastream_dlo_refresh_history.htm&type=5&language=en_US) |
| Data Explorer display | Maximum 100 rows per view | [Data Explorer](https://help.salesforce.com/s/articleView?id=data.c360_a_view_your_data.htm&type=5&language=en_US) |

## Check yourself

- Why might an admin be unable to add a field to a DLO from the Data Lake Objects tab?
- When would a date in Data Explorer show as 01/01/1901?
- Why might SOQL copied from Data Explorer return fewer columns than the table has?
- Which DLOs show record-level refresh statistics?

## Sources

- [Data Mapping](https://help.salesforce.com/s/articleView?id=data.c360_a_data_mapping.htm&type=5&language=en_US)
- [Data Mapping Requirements in Data 360](https://help.salesforce.com/s/articleView?id=data.c360_a_required_data_mappings.htm&type=5&language=en_US)
- [Data Objects in Data 360](https://help.salesforce.com/s/articleView?id=data.c360_a_data_lake_objects.htm&type=5&language=en_US)
- [Data Builds the Foundation for Marketing](https://help.salesforce.com/s/articleView?id=data.c360_a_datacloud_mktgnext.htm&type=5&language=en_US)
- [Prepare and Model Data](https://help.salesforce.com/s/articleView?id=data.c360_a_prepare_and_model_data.htm&type=5&language=en_US)
- [Simple Start in Data 360](https://help.salesforce.com/s/articleView?id=data.c360_a_simple_start.htm&type=5&language=en_US)
- [Activate Data Stream Sync for Data 360](https://help.salesforce.com/s/articleView?id=data.c360_a_activate_data_stream_sync_for_data360.htm&type=5&language=en_US)
- [Simple Start Limitations and Key Considerations](https://help.salesforce.com/s/articleView?id=data.c360_a_limitations_considerations_for_simple_start.htm&type=5&language=en_US)
- [Data Stream and Data Lake Object Refresh History](https://help.salesforce.com/s/articleView?id=data.c360_a_datastream_dlo_refresh_history.htm&type=5&language=en_US)
- [View Your Data in Data Explorer](https://help.salesforce.com/s/articleView?id=data.c360_a_view_your_data.htm&type=5&language=en_US)
- [Optimize Identity Resolution](https://help.salesforce.com/s/articleView?id=data.c360_a_identity_resolution_optimize.htm&type=5&language=en_US)
- [Set Up Personalization Features in Marketing Cloud Next](https://help.salesforce.com/s/articleView?id=mktg.mktg_data_graph_setup.htm&type=5&language=en_US)
- [Manage Data Sources for Personalizing Content](https://help.salesforce.com/s/articleView?id=mktg.mktg_content_personalization_data_sources.htm&type=5&language=en_US)
- [Category](https://help.salesforce.com/s/articleView?id=data.c360_a_category.htm&type=5&language=en_US)
- [Activation for Data 360 Data Model Objects](https://help.salesforce.com/s/articleView?id=data.c360_a_dmo_activation.htm&type=5&language=en_US)
- [Understanding Segmentation in Marketing Cloud Next](https://help.salesforce.com/s/articleView?id=mktg.mktg_audiences_segmentation.htm&type=5&language=en_US)
- [People Records in Marketing Cloud Next](https://help.salesforce.com/s/articleView?id=mktg.mktg_audiences_people_records.htm&type=5&language=en_US)
- [Data Mapping Best Practices](https://help.salesforce.com/s/articleView?id=data.c360_a_data_mapping_best_practices.htm&type=5&language=en_US)
- [Marketing Cloud Next Consultant Exam Guide](https://help.salesforce.com/s/articleView?id=005387657&language=en_US&type=1)

## About the full unit

The "Core concepts", "Exam traps" and "Worked scenario" sections of this unit, its 8 linked practice questions, and unlimited timed mock exams are included with the Marketing Cloud Next Consultant pack (USD $19): https://www.certifyforce.com/practice-exams