Is this performance issue only with reports? I have seen issues where upgrade tool drops certain database indices. It is worth ensuring the presence of all required indices. https://support.ptc.com/appserver/cs/view/solution.jsp?n=CS98135.
Please update the database stats as well.
Also use of like operator with leading wild characters reduces the chance of using index than using a equal operator on a field which is covered by indexes. You can try to profile the action to identify where the time is actually spent.
Thanks
Binesh
Barry Wehmiller International