Statistics Creation on Tables and Stat Subsets to Enable Faster Join Queries - response (1) by M.Saeed Khurram

Hi,
The best way to check the required stats is to use help stats diagnostics.
You can use it as follows:

DIAGNOSTIC HELPSTATS ON FOR SESSION;

Explian Your_Query

Then go to the end of explain plan and collect the recomended stats for the joins.
 
Secondly if your joins are based on Primary index then the stats collection on index columns will be enough to optimize joins.