Which query is better inner join or in???

[tamilselvan]

You don't need to select "detail.p_date AS grp0" column.

Try this:

 SELECT COUNT(*) 
 FROM (
    SELECT distinct a.pkey   
       FROM detail a, agg_tbl b
     WHERE TO_CHAR(a.pkey) = b.detail_pkey
         AND b.agg_id  = '0b080e0000010876d429ad0a1428098500' );

Tamil