there is a sql statement that was executed over 5 million times over the period of the batch job was ran, it is used bind variable, I wonder if there is anything esle that we can do to make it run faster.
If it were me, I would just run the query less often...

If this query really runs 5 million times, then it needs to be really efficient. You can also create a temporary table with the data you want in a demormalized format, then just loop through the query.

If you can do something with a single SQL statement then do so, otherwise look at PL/SQL collections and or temporary tables.