Pyramid Allows to Drill Down a Member Although There Aren't Any Children
We have noticed that on some scenarios, when using Rugged Hierarchy, Pyramid allows to drill down on a member although it doesn't have any children.
Upon further investigation, we found that this is related to a known SSAS issue where AS doesn't return a precise child count to the client.
Here is a explanation of the issue as described by the Microsoft Analysis Services Team:
AS (Analysis Services) only returns precise child count to the client when it is inexpensive to do so. Some AS clients use the child count to decide whether to allow users to expand a member node in the UI. In those cases, the clients really only want to know whether there is at least one child or not. To improve performance, the design returns 1000 as child count to indicate there is at least one child. AS does return accurate child count for materialized natural hierarchies and when there are no other complications which would change the child count. But AS would simply return 1000 when there is dimension security, when the hierarchy is unmaterialized, when there are ragged holes, etc.