---
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id: 1ae8ce0d7232aaae4c7b6a0da6d2074b5632d273ec87dc5e6bba9acb13bfd35e
title: Using an Existing Data Lake Object to Create a Data Stream
collection: admin
version: current
locale: en-us
portal_url: https://docs.salesforce.com/admin/current/en-us/data/264-0-0/c360_a_guardrails_existing_data_lake_object.md
canonical_url: https://help.salesforce.com/s/articleView?id=data.c360_a_guardrails_existing_data_lake_object.htm&release=264.0.0&type=5
source_site: help.salesforce.com
content_type: documentation
content_hash: 379fd52173e1acbc04f81f37373e8f6daa528f3a22300524bd63cd4e19df1d42
description: You can use an existing data lake object (DLO) when creating an S3, Google Cloud Storage, or SFTP data stream. The data stream that initially created the DLO defines the characteristics, such as the primary key, event date time, and record modified field. You can convey how the new data stream’s fields conform to the existing DLO fields.
products:
  - Data 360
release: "264"
---
# Using an Existing Data Lake Object to Create a Data Stream

You can use an existing data lake object (DLO) when creating an S3, Google Cloud Storage, or SFTP data stream. The data stream that initially created the DLO defines the characteristics, such as the primary key, event date time, and record modified field. You can convey how the new data stream’s fields conform to the existing DLO fields.

Keep these considerations in mind when using an existing DLO to create a data stream.

- You can’t use a DLO that’s already being used by another source.
- Bring in all data stream fields. If the DLO doesn’t have a field that corresponds to your data stream field, you can extend the DLO on the Data Lake Object tab.
- A data stream field must have the same data type as its intended DLO target field. If you can’t locate the DLO field in the dropdown, it’s because of a data type mismatch or another data stream field is using the DLO field.
- Assign a data stream field to the DLO’s primary key.
- If the DLO is in the Engagement category, assign a data stream field to the DLO’s Event Date Time.
- If the DLO is of category Profile and the Record Modified field was previously declared on the DLO, assign a data stream field to it. If the Record Modified field hasn’t been previously assigned, you can configure it during data stream setup.
- If the Organization Unit Identifier was previously declared on the DLO, assign a data stream field to it. If it hasn’t been previously assigned, you can configure it during data stream setup.