---
schema_version: "1"
id: 5c25630a1409e327312a2f0983b33d9e2de1885f811d5e9aa77b2e40ed6d3129
title: Sync an External Data Source for Salesforce Connect
collection: admin
version: current
locale: en-us
portal_url: https://docs.salesforce.com/admin/current/en-us/platform/264-0-0/platform_connect_considerations_sync.md
canonical_url: https://help.salesforce.com/s/articleView?id=platform.platform_connect_considerations_sync.htm&release=264.0.0&type=5
source_site: help.salesforce.com
content_type: documentation
content_hash: 6d19bde056555c565d46759e7e2510295499419af90f9190ed17f5a0c417fddb
description: When you validate and sync an external data source, it creates or overwrites Salesforce external objects that map to the external system’s schema. Syncing doesn’t copy any data into your Salesforce org or write data from your org to the external system.
products:
  - Salesforce Platform
  - Security
release: "264"
---
# Sync an External Data Source for Salesforce Connect

When you validate and sync an external data source, it creates or overwrites Salesforce external objects that map to the external system’s schema. Syncing doesn’t copy any data into your Salesforce org or write data from your org to the external system.

### Required Editions

<table class="slds-table slds-table_bordered slds-max-medium-table_stacked slds-m-bottom_small edition">
      <colgroup>
        <col>
      </colgroup>
      <tbody>
        <tr class="">
          <td class="slds-cell-wrap" style="vertical-align:top;">Available in: both Salesforce Classic and Lightning Experience (not for high-data-volume
            external objects)</td>

        </tr>
        <tr class="">
          <td class="slds-cell-wrap" style="vertical-align:top;">
            <p>Available in: <strong>Developer</strong> Edition</p>
            <p style="margin-bottom:0;">Available for an extra cost
              in: <strong>Enterprise</strong>, <strong>Performance</strong>, and <strong>Unlimited</strong>
              Editions</p>
          </td>

        </tr>
      </tbody>
    </table>

Syncing fails if it causes your org to exceed 200 external objects. Syncing also fails if it tries to create an external object with an API name that conflicts with an existing object in the org. In such cases, determine whether the existing object is needed.

- If the object isn’t needed, delete that object, and sync again.
- If the object is needed, change the API name of the existing object to no longer conflict with the table that you're trying to sync. However, if the existing object is an external object that was previously synced, you can’t resync it. Manually update the external object and its fields as needed for schema changes on the external system.

![Tip](https://sf-zdocs-cdn-prod.zoominsoftware.com/tdta-platform-extend_click-264-0-0-production-enus/5f7d9219-b7b1-4552-8891-f1aba9b289fc/images/icon_tip.png)

Tip We recommend that you create your external data sources and external objects in a Developer Edition org. Then use managed packages to deploy the external data sources and external objects to your other orgs. Doing so prevents your external object names from conflicting with other objects in your org by applying a namespace prefix.

When an external object is created via syncing, its Deployment Status is set to In Development. When you’re ready to expose the external object to users, set the status to Deployed.

If the external system’s schema changes, the modifications aren’t automatically synced to your Salesforce org. To reflect the changes in the external system, resync the objects. After resyncing, all users who have the same profile as the user who initiated the resync are granted field-level access to the external objects. When you resync an external object:

- The Display URL Reference Field is set to None.
- If a custom field has the Is Name Field attribute, the attribute is removed. The External ID standard field is used as the name field of the external object.
- The Deployment Status doesn’t change.

To understand how syncing affects relationship fields on external objects, see [Relationships on External Objects](https://help.salesforce.com/s/articleView?id=relationships_considerations.htm&language=en_US).

#### See Also

- [Salesforce Connect](https://help.salesforce.com/s/articleView?id=platform.platform_connect_about.htm&release=264.0.0&type=5 "Salesforce Connect provides seamless integration of data across system boundaries by letting your users view, search, and modify data that’s stored outside your Salesforce org. For example, perhaps you have data that’s stored on premises in an enterprise resource planning (ERP) system. Instead of copying the data into your org, you can use external objects to access the data in real time via web service callouts.")
- [Salesforce Platform Features Supported by Salesforce Connect](https://help.salesforce.com/s/articleView?id=platform.platform_connect_considerations.htm&release=264.0.0&type=5 "Salesforce Connect provides seamless integration with the Salesforce Platform and enables users to view, search, and modify external object data.")
- [Deployment Status for Custom Objects and External Objects](https://help.salesforce.com/s/articleView?id=deploying_custom_objects.htm&language=en_US)
- [Validate and Sync an External Data Source](https://help.salesforce.com/s/articleView?id=platform.ext_data_sync_database.htm&release=264.0.0&type=5 "After you configure an external data source, synchronize it to map its tables with external objects in your Salesforce org. The content and data of external objects appear in federated search, together with your Salesforce content and data.")