WITH CLAUSES - need advice

Question

Recently we found that the server converts all the request to 'with clauses' format in the physical query even if the request does not contain any subquery. I am bit concerned on this as some article suggest that there is a limitation in using with clauses and it can return unexpected results. Could this change in behavior cause some problem?

Answer 1

Hi all,
We are currently using ORACLE 10g.
For ex the original query for a specific report would look like
select distinct D1.c1 as c1,
D1.c2 as c2
from
(select distinct T41994.NAME as c1,
T41994.LOC as c2
from
(SELECT
A.*,
ORA62102.F_UTC2LOCAL(A.CREATED_TS,'(GMT-08:00) Pacific Time (US & Canada); Tijuana') AS CREATED_LCL,
ORA62102.F_UTC2LOCAL(A.LAST_UPD,'(GMT-08:00) Pacific Time (US & Canada); Tijuana') AS LAST_UPD_LCL,
ORA62102.F_UTC2LOCAL(A.REFERENCE_START_DT,'(GMT-08:00) Pacific Time (US & Canada); Tijuana') AS REFERENCE_START_DT_LCL,
ORA62102.F_UTC2LOCAL(A.INDEXED_DATE_0,'(GMT-08:00) Pacific Time (US & Canada); Tijuana') AS INDEXED_DATE_0_LCL
FROM ORA62102.S_ORG_EXT A) T41994
where ( T41994.BU_ID = '1-D3DGK' and T41994.DELETED_STATE = 'N' )
) D1
Now the query is changed to the following format
WITH
SAWITH0 AS (select distinct T41994.NAME as c1,
T41994.LOC as c2
from
(SELECT
A.*,
ORA62105.F_UTC2LOCAL(A.CREATED_TS,'(GMT-08:00) Pacific Time (US & Canada); Tijuana') AS CREATED_LCL,
ORA62105.F_UTC2LOCAL(A.LAST_UPD,'(GMT-08:00) Pacific Time (US & Canada); Tijuana') AS LAST_UPD_LCL,
ORA62105.F_UTC2LOCAL(A.REFERENCE_START_DT,'(GMT-08:00) Pacific Time (US & Canada); Tijuana') AS REFERENCE_START_DT_LCL,
ORA62105.F_UTC2LOCAL(A.INDEXED_DATE_0,'(GMT-08:00) Pacific Time (US & Canada); Tijuana') AS INDEXED_DATE_0_LCL
FROM ORA62105.S_ORG_EXT A) T41994
where ( T41994.BU_ID = '1-D3DGK' and T41994.DELETED_STATE = 'N' ) )
select distinct SAWITH0.c1 as c1,
SAWITH0.c2 as c2
from
SAWITH0
Even if I select 2 columns from a table , the select clause in the physical query in OBI server contains 'with clause'.
-Uma