Join two tables using like statement - response (5) by VandeBergB

most of these solutions will "work", but they all have one fatal flaw, they force a full table scan of T1, the column that you are using a function to evaluate.  depending upon the size of the table, you would probably be better off if you created another column and updated it to "...position(trim(t1.ColA)", collected stats on it and used the new column in the join.
using any kind of function in the join clause will dramatically increase the spool used and performance will suffer as well.