Umbraco-CMS/src/Umbraco.Web.UI.NetCore/appsettings.json

{
    "ConnectionStrings": {
        "umbracoDbDSN": "Data Source=|DataDirectory|\\Umbraco.sdf;Flush Interval=1;"
    },
    "Umbraco": {
        "CMS": {
            "ModelsBuilder": {
                "ModelsMode":  "PureLive"
            }
        }
    }
}