次のメソッドは、インラインビューを削除して重複をフェッチし、REGEXP_REPLACEを使用します。 およびRTRIM LISTAGGで aggregated listで個別の結果セットを取得する関数 。したがって、複数のスキャンを実行することはありません。
この部分をコードに追加します、
RTRIM(REGEXP_REPLACE(listagg (tm_redir.team_code, ',')
WITHIN GROUP (ORDER BY tm_redir.team_code),
'([^,]+)(,\1)+', '\1'),
',')
変更されたクエリ-
SQL> with tran_party as -- ALL DUMMY DATA ARE IN THESE CTE FOR YOUR REFERENCE
2 (select 1 tran_party_id, 11 transaction_id, 101 team_id_redirect
3 from dual
4 union all
5 select 2, 11, 101 from dual
6 union all
7 select 3, 11, 102 from dual
8 union all
9 select 4, 12, 103 from dual
10 union all
11 select 5, 12, 103 from dual
12 union all
13 select 6, 12, 104 from dual
14 union all
15 select 7, 13, 104 from dual
16 union all
17 select 8, 13, 105 from dual),
18 tran as
19 (select 11 transaction_id, 1001 account_id, 1034.93 amount from dual
20 union all
21 select 12, 1001, 2321.89 from dual
22 union all
23 select 13, 1002, 3201.47 from dual),
24 account as
25 (select 1001 account_id, 111 team_id from dual
26 union all
27 select 1002, 112 from dual),
28 team as
29 (select 101 team_id, 'UUU' as team_code from dual
30 union all
31 select 102, 'VV' from dual
32 union all
33 select 103, 'WWW' from dual
34 union all
35 select 104, 'XXXXX' from dual
36 union all
37 select 105, 'Z' from dual)
38 -- The Actual Query
39 select a.account_id,
40 t.transaction_id,
41 (SELECT RTRIM(
42 REGEXP_REPLACE(listagg (tm_redir.team_code, ',')
43 WITHIN GROUP (ORDER BY tm_redir.team_code),
44 '([^,]+)(,\1)+', '\1'),
45 ',')
46 from tran_party tp_redir
47 inner join team tm_redir
48 on tp_redir.team_id_redirect = tm_redir.team_id
49 inner join tran t_redir
50 on tp_redir.transaction_id = t_redir.transaction_id
51 where t_redir.account_id = a.account_id
52 and t_redir.transaction_id != t.transaction_id)
53 AS teams_redirected
54 from tran t inner join account a on t.account_id = a.account_id
55 /
ACCOUNT_ID TRANSACTION_ID TEAMS_REDIRECTED
---------- -------------- --------------------
1001 11 WWW,XXXXX
1001 12 UUU,VV
1002 13
SQL>