xxx while the managed IDbConnection interface was being used: Login failed for user xxx

Process cube的时候遇到如下错误.

Errors in the high-level relational engine. The following exception occurred while the managed IDbConnection interface was being used: Login failed for user xxx

解决这个问题的步骤：（reset impression mode）

Note:  to set to the impersonation option:
1.) Within the Solution Explorer, right-click on your data source,
2.) Select 'View Designer' from within the pop-up menu
3.) Click on the 'Impersonation Information' tab
4.) Select the 'Default' option （或者尝试windows用户帐号或者service帐号）
5.) Click Ok

参考链接：Errors in the high-level relational engine.