Correlated SubQuery needs Tuning.. INDEX and LENGTH functions causing problem - forum topic by Akshay.Shaha

Hi All,
I have scenario like below:

Requirement - Need to select ID values those are present ( hidden)  in DESCR column. But no joining condition in both the tables.
Query I have used -

 
Problem Faced - Query is working correctly as per requirement. But in Production environment it getting rejected bcoz of some Product Join Rejection rule.
                            I tried running explain plan,  though with minimal of data it is showing 1 hours and 30 minutes for subquery only.
 
Can anyone please suggest how should subquery be tuned ?
 
PS : I can not use Cross join !!If I remove INDEX and Length function is Substr , query is working fine !!
 
Many Thanks in advance..!!