According to ITIL Service Operation book the purpose of a KEDB is to allow storage of previous knowledge of incidents and problems and how they were overcome to allow quicker diagnosis and resolution if they recur.
A lot of BMC product "consultants" have a confusion regardingng KEDB and Knowledge Management BMC Module.
From a best practice perspective Knowledge Management is a process wich purpose is to share perspectives, ideas, experience and information; to ensure that these are available in the right place at the right time to enable informed decision, to make this possible this process use a Service Knowledge and Management System.
At BMC SW I have not found the KEDB within Problem Management Module, can you please get me some ideas other than using Knowledge Management BMC Module???
If you are referencing the BMC Remedy ITSM Suite, you can create known error records within the problem management module which will be visible within the incident management module. This is explained in the BMC Remedy Service Desk: Problem Management User guide on page 97.