---
schema_version: "1"
id: b571cb816215942465f042a535b616ebe1ebe89418dd4e4e9c563ef9f3ef52f3
title: Sync Considerations for Salesforce Connect—Custom Adapter
collection: admin
version: current
locale: en-us
portal_url: https://docs.salesforce.com/admin/current/en-us/platform/264-0-0/apex_considerations_sync.md
canonical_url: https://help.salesforce.com/s/articleView?id=platform.apex_considerations_sync.htm&release=264.0.0&type=5
source_site: help.salesforce.com
content_type: documentation
content_hash: d98e2f1b43b04995f1f485143e028ee35d73e7b1f83f8f7736508001c44863b7
description: "When you validate and sync an external data source of type Salesforce Connect: Custom, some special behaviors and limitations apply."
products:
  - Salesforce Platform
  - Security
release: "264"
---
# Sync Considerations for Salesforce Connect—Custom Adapter

When you validate and sync an external data source of type `Salesforce Connect: Custom`, some special behaviors and limitations apply.

### 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 always enables search on the external object when search is enabled on the external data source, and vice versa. For an external data source of type Salesforce Connect: Custom, search is enabled when the custom adapter’s `DataSource.Provider` class declares the `DataSource.Capability.SEARCH` capability.

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

Important When you select the tables to sync, determine whether check marks appear in the Synced column.

If a Synced check mark appears, your org has an external object whose object name matches the table name. If you select the table and click **Sync**:

- The external object is overwritten.
- Any custom field on the external object is overwritten if its API name (for example, `Email__c`) associates it with a table column name (for example, `Email`).
- Any other custom fields on the external object remain as they are, including:
    - Previously synced custom fields whose API names were changed by editing their Field Name values.
    - Manually added custom fields whose API names aren’t associated with table column names.

If no Synced check mark appears, and you sync the table, a new external object is created in your org. The new external object’s object name matches the table name.

For example, suppose you change the table name in the custom adapter’s `DataSource.Connection` class to no longer match the object name of the external object. Syncing that table creates a new external object in Salesforce. We recommend that you change the object name of the existing external object to match the new table name in the `DataSource.Connection` class before you sync that table.

Also review the considerations that apply to all Salesforce Connect adapters.

#### See Also

- [Sync an External Data Source for Salesforce Connect](https://help.salesforce.com/s/articleView?id=platform.platform_connect_considerations_sync.htm&release=264.0.0&type=5 "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.")
- [Define an External Data Source for Salesforce Connect—Custom Adapter](https://help.salesforce.com/s/articleView?id=platform.apex_add_external_data_source.htm&release=264.0.0&type=5 "Connect your Salesforce org to any data anywhere via a Salesforce Connect custom adapter that you create with the Apex Connector Framework.")
- [Custom Adapter for Salesforce Connect](https://help.salesforce.com/s/articleView?id=platform.apex_adapter_about.htm&release=264.0.0&type=5 "Connect to any data anywhere for a complete view of your business. Use the Apex Connector Framework to develop a custom adapter for Salesforce Connect.")