Customer Accounts that have Non Primary Phone Contact Points only

I was asked to provide a list of customer accounts that have
1. No primary phones associated with the account
2. Have non-primary phone associated with the account

So I translated the given requirement into sql query as given below

SELECT account_number
  FROM hz_cust_accounts hca
 WHERE NOT EXISTS ( SELECT 1
                      FROM hz_contact_points hcp
                     WHERE contact_point_type = 'PHONE'
                       AND owner_table_name   = 'HZ_PARTIES'
                       AND owner_table_id     = hca.party_id
                       AND primary_flag       = 'Y'
                  )
   AND EXISTS     ( SELECT 1
                      FROM hz_contact_points hcp
                     WHERE contact_point_type    = 'PHONE'
                       AND owner_table_name      = 'HZ_PARTIES'
                       AND owner_table_id        = hca.party_id
                       AND NVL(primary_flag,'N') = 'N'
                  )

This query was very slow. There were not too many customer accounts that met the above condition. I thought about it and used the following query. It was much better.

SELECT /*+ use_nl ( phone ca) */
       account_number
  FROM hz_cust_accounts ca
     , (SELECT owner_table_id
          FROM ( SELECT owner_table_id
                      , SUM(DECODE(primary_flag,'Y',1,0)) primary_count
                      , SUM(DECODE(primary_flag,'Y',0,1)) non_primary_count
                   FROM hz_contact_points
                  WHERE status = 'A'
                    AND contact_point_type = 'PHONE'
                    AND owner_table_name   = 'HZ_PARTIES'
                  GROUP BY owner_table_id
               )
         WHERE primary_count = 0 AND non_primary_count > 0
       ) phone
  WHERE ca.party_id = phone.owner_table_id

I think this query can give better information about objects that have only non-primary phones

SELECT owner_table_name, owner_table_id
  FROM ( SELECT owner_table_name, owner_table_id
             , SUM(DECODE(primary_flag,'Y',1,0)) primary_count
             , SUM(DECODE(primary_flag,'Y',0,1)) non_primary_count
          FROM apps.hz_contact_points
         WHERE status = 'A'
           AND contact_point_type= 'PHONE'
         GROUP BY owner_table_name, owner_table_id
       )
 WHERE primary_count = 0 AND non_primary_count > 0