When we create the project there will be default filter available in Linked Defects tab under both the instances Test Plan module and Test Lab in QC 9.0. Could anyone help me on the following:

1. Why this filter is appearing by default?
2. Under which table this default filter is getting stored?
3. If we clear the filter from our system then only for that individual the filter will get cleared. So how to delete this filter for all the users in that project?
4. How to avaoid this filter getting created while creating the project?