I have a SharePoint calender list and where i have given item level permissions for each event through designer workflow using the impersonation step. But now on the production site the number of events in the list have reached 18000 and the item level permissions are making my custom control very slow.
I have found that a stored procedure called "proc_GetUniqueScopesInList" takes about 3000 ms to execute.
So is there a way where i can remove the item level permissions but still maintain the security level?