Urgen!! Query takes lots of time to execute and the production is in effect

Question

Hi,
We have some data loading script. This scripts takes lots of time to execute. As Iam new to tunning please do let me know what is the wrong with the query !!
Thanks In advance
Query:
=========
INSERT /*+ PARALLEL */ INTO ris.ris_pi_profile
(ID,COUNTRY_OF_CITIZENSHIP,IMMIGRATION_STATUS,SSN,DOB,GENDER,
ETHNICITY,RACE,DEPARTMENT,DIVISION,INSTITUTION_ID,INST_EMAIL,EFFECT_DATE,ACADEMIC_TITLE,ACADEMIC_POSITION,
OTH_PER_DATA,PCT_RESEARCH,PCT_TEACHING,PCT_CLINICAL,PCT_ADMIN,PCT_OTHER,PCT_TRAINING)
SELECT
ap.id,
p.citizen_cd,
decode(p.visa_cd,'CV',0,'F1',1,'H1',2,'H1B',3,'H2',4,'J1',5,'J2',6,'O1',7,'PR',8,'PRP',9,'TC',10,'TN',11,'TNN',12),
(select n.soc_sec_num from sa.name n where n.name_id = p.name_id),
(select n.birth_date from sa.name n where n.name_id = p.name_id),
(select decode(n.gender_cd,'F',1,'M',2,0) from sa.name n where n.name_id = p.name_id),
(select decode(n.ethnic_cd,'H',1) from sa.name n where n.name_id = p.name_id),
(select decode(n.ethnic_cd,'A',2,'B',3,'I',1,'P',4,'W',5) from sa.name n where n.name_id = p.name_id),
a.dept_name,
a.div_name,
a.inst_id,
(select n.email from sa.name n where n.name_id = p.name_id),
a.eff_date,
ac.acad_pos_desc,
p.acad_pos_cd,
0,
p.research_pct,
p.teach_pct,
p.patient_pct,
p.admin_pct,
p.other_pct,
p.course_pct
FROM
appl1 ap,
sa.personal_data p,
sa.address a,
sa.academic_pos_cd ac,
profile_pi f
WHERE
p.project_role_cd='PI'
and ap.appl_id=f.appl_id
and p.appl_id=f.appl_id
and p.name_id=f.name_id
and a.addr_id=f.addr_id
and p.acad_pos_cd=ac.acad_pos_cd
AND EXISTS (select 1 from ris.ris_institution i WHERE i.id = a.inst_id)
AND EXISTS (select 1 from sa.academic_pos_cd acp WHERE acp.acad_pos_cd = p.acad_pos_cd);
In the execution PLan I see lots of Nested loop, Hash Join
Index( Unique scan)
Table Access by ( Index rowid)
This query is fast in Test DB but ver very slow in prod DB. Need your help Urgent.
Minaz

Answer 1

When your query takes too long...
When your query takes too long ...