DB Link Query занимает слишком много времени

Question

У меня есть этот запрос, содержащий ссылку dblink, так как мне нужно подключиться к другой базе данных, и он кажется таким медленным. Есть ли способ сделать это быстро? В другом запросе dblink, выполняемом в Mse c, но один и тот же запрос будет использоваться на другом сервере, тогда его выполнение занимает слишком много времени. Индекс уже создан на сервере ссылок БД. Есть ли какие-либо проблемы в запросе.

Ниже запрос используется для получения последних счетов.

Ниже приведен код:

WITH recursive derived AS
      (  SELECT inv_num, new_inv_num, 0 AS LEVEL
          FROM "CBF".cbf_inv_gen_trans@prod_lbt_temp_cluster123 o ,
        "CBF".bill_master@prod_lbt_temp_cluster123 bm
         WHERE  bm.invoice_no = o.new_inv_num
         AND BM.id::number = o.batch_id::number 
         AND  o.inv_num = '061810G10024409'
           AND o.new_inv_num NOT LIKE '%XX%'
           AND o.new_inv_num IS NOT NULL
           AND o.attribute_id IS NOT NULL
           AND o.attr_val IS NOT NULL
           AND bm.bill_date is not null
           UNION
               SELECT distinct o.inv_num, cr.new_inv_num, 0 AS LEVEL
          FROM "CBF".cbf_inv_gen_trans@prod_lbt_temp_cluster123 o , "CBF".cbf_inv_gen_trans@prod_lbt_temp_cluster123 CR, 
          "CBF".bill_master@prod_lbt_temp_cluster123 bm
         WHERE  o.new_inv_num = cr.inv_num
         and bm.invoice_no = cr.new_inv_num
          AND BM.id::number = cr.batch_id::number
        AND o.inv_num = '061810G10024409'
        and o.new_inv_num ilike '%XX%'
        AND o.attribute_id IS NOT NULL
        and cr.new_inv_num not  ilike '%XX%'
        and cr.attribute_id ='38'
        AND bm.bill_date is not null
        UNION
          select ad.invoice_no,ad.new_inv_num, 0 AS LEVEL
            from "CBF".cbf_custom_attr_value_details@prod_lbt_temp_cluster123 ad ,"CBF".bill_master@prod_lbt_temp_cluster123 bm
        WHERE bm.invoice_no = ad.new_inv_num
         AND BM.id::number = ad.batch_id::number 
         AND attribute_id = 129 and 
             new_inv_num is not null 
             and new_inv_num not like '%XX%'
             and ad.invoice_no = '061810G10024409'
              AND bm.bill_date is not null
             ), MERGE as (
             SELECT * 
            FROM derived
            union all
                SELECT e.inv_num, e.new_inv_num, LEVEL + 1
                  FROM "CBF".cbf_inv_gen_trans@prod_lbt_temp_cluster123 e
                 inner join MERGE s ON s.new_inv_num = e.inv_num
                 inner JOIN "CBF".BILL_MASTER@prod_lbt_temp_cluster123 bm 
                 ON BM.INVOICE_NO = e.NEW_INV_NUM  and BM.id::number = e.batch_id::number 
                 WHERE e.new_inv_num NOT LIKE '%XX%'
                   AND e.new_inv_num IS NOT NULL
                   AND e.attribute_id IS NOT NULL
                   AND e.attr_val IS NOT NULL
                   AND BM.BILL_DATE IS NOT NULL
                ),
        RECREATE AS (***
                 SELECT * 
            FROM derived
            union all
            select ad.invoice_no,ad.new_inv_num,LEVEL + 1
                    from "CBF".cbf_custom_attr_value_details@prod_lbt_temp_cluster123 ad
                     inner join RECREATE s ON s.new_inv_num = ad.invoice_no
                     inner JOIN "CBF".BILL_MASTER@prod_lbt_temp_cluster123 bm ON
                      BM.INVOICE_NO = ad.NEW_INV_NUM  and BM.id::number = ad.batch_id::number 
                     where attribute_id = 129  
                     AND ad.new_inv_num is not null 
                     and ad.new_inv_num not like '%XX%'
                     AND BM.BILL_DATE IS NOT NULL
                )
       Select new_inv_num INTO  v_new_inv_num from (SELECT * from MERGE 
          union
          select * from RECREATE
    )
           WHERE LEVEL  in (select MAX(LVL) from (
                SELECT max(LEVEL) LVL FROM MERGE
                UNION 
                SELECT max(LEVEL) LVL FROM RECREATE
                UNION 
                SELECT max(LEVEL) LVL FROM derived )
            ) limit 1;