Hi Timour, In regular maria-5.5, I get: (gdb) wher 1 #0 Item_func_like::select_optimize (this=0xa11c478) at /home/psergey/dev2/5.5-look7/sql/item_cmpfunc.cc:4739 (More stack frames follow...) (gdb) p args[1] $123 = (Item_singlerow_subselect *) 0xa1194a0 (gdb) p args[1]->used_tables() $124 = 0 (gdb) p args[1]->const_item() $125 = true In 5.5-timour tree, I get: #1 0x0841a035 in Item_func_like::select_optimize (this=0xa109820) at /home/psergey/dev2/5.5-timour/sql/item_cmpfunc.cc:4739 (gdb) p args[1] $47 = (Item_singlerow_subselect *) 0xa106848 (gdb) p args[1]->used_tables() $49 = 0 (gdb) p args[1]->const_item() $51 = false I also put a breakpoint in JOIN::get_examined_rows(), it is never hit. Can you explain this effect? BR Sergei -- Sergei Petrunia, Software Developer Monty Program AB, http://askmonty.org Blog: http://s.petrunia.net/blog