Applies to SharePoint 2016, can be adapted for O365
If you’re connecting to an external list of significant size, you may run into the following error:
Database Connector has throttled the response. The response from database contains more than ‘2000’ rows. The maximum number of rows that can be read through Database Connector is ‘2000’. The limit can be changed via the ‘Set-SPBusinessDataCatalogThrottleConfig’ cmdlet.
1. Log into your SharePoint server
2. Open your SharePoint 2016 Management Shell as administrator (right-click, run as administrator)
3. Connect to your site
Connect-Site -url https://sharepoint.contoso.com
4. Get ALL service application Proxy IDs (you’ll need this in a later step)
Get-SPServiceApplicationProxy
5. Note the ID of the “Business Data Con…” application

6. Set a new variable “$serviceapp” to that app using the ID you noted as its identity
$serviceapp = Get-SPServiceApplicationProxy -Identity a12b3cf4-d12j...

7. Run the following cmdlet to increase the throttle limit
Get-SPBusinessDataCatalogThrottleConfig -Scope Database -ThrottleType Items -ServiceApplicationProxy $serviceapp | Set-SPBusinessDataCatalogThrottleConfig -Maximum 1000000000 -Default 500000
Your external list will now load correctly!
And how do you “adapt” this to Office 365?