merge CTE query in Oracle - sql

Question

I am looking for an optimized way to merge CTE query as mentioned below. In the below query, the same table is getting hit twice, I am looking for an option to hit this table once and it will only be possible if I remove CTE and put everything into single query. I am using CTE as I need to derive column value and then compare that value..
Query
with cte as
(
select distinct
'UP' search_update_code,
'G' search_prov_entity_type,
prpr.prpr_id search_prov_id,
prpr.mctn_id search_tax_id,
'UP' group_provdata_upd_cd,
'G' group_provdata_entity,
case
when enroll_type = 'AH' THEN 'A'
when enroll_type = 'VP' THEN 'A'
when enroll_type = 'CK' THEN ' '
end group_provdata_clm_eft_pay_ind <-- deriving values here
from
fsg_prcb_pe_enroll_stream prcb
inner join
cmc_prpr_prov prpr on prpr.mctn_id = prcb.prov_tin_number <-- 1st hit
where
prpr.prpr_entity ='G'
and prcb.prov_tin_number = ?
and prcb.error_flag is null
)
select distinct
cte.*
from cte
inner join cmc_prpr_prov prpr on cte.search_prov_id = prpr.prpr_id <-- 2nd hit
where cte.group_provdata_clm_eft_pay_ind <> prpr.prpr_cl_eft_ind <--- comparing derived values here
and prpr_term_dt >= systimestamp

Answer 1

You can rewrite your query like below:
with cte as
(
select distinct
'UP' search_update_code,
'G' search_prov_entity_type,
prpr.prpr_id search_prov_id,
prpr.mctn_id search_tax_id,
'UP' group_provdata_upd_cd,
'G' group_provdata_entity,
case
when enroll_type = 'AH' THEN 'A'
when enroll_type = 'VP' THEN 'A'
when enroll_type = 'CK' THEN ' '
end group_provdata_clm_eft_pay_ind, <-- deriving values here
prpr.prpr_cl_eft_ind prpr_cl_eft_ind_2,
prpr_term_dt
from
fsg_prcb_pe_enroll_stream prcb
inner join
cmc_prpr_prov prpr on prpr.mctn_id = prcb.prov_tin_number <-- 1st hit
where
prpr.prpr_entity ='G'
and prcb.prov_tin_number = ?
and prcb.error_flag is null
)
select distinct
cte.*
from cte
where group_provdata_clm_eft_pay_ind <> prpr_cl_eft_ind_2 <--- comparing derived values here
and prpr_term_dt >= systimestamp