optimizer_index_cost_adj hint

Sometimes you want to use alter session set optimizer_index_cost_adj=<value> to change the parameter, but you can also use hint for the purpose, for example:

select /*+ opt_param('optimizer_index_cost_adj',20) */ col1, col2 . .
  

And optimizer_mode hint:

select /*+ opt_param('optimizer_mode','first_rows_10') */ col1, col2 . . .