Need Tuning Help

Question

I have difficulty in tuning the following query;
SELECT T01.*,T04.address_line,T04.city,T04.state,T05.country_name
FROM v_contact T01 INNER JOIN v_contact_alignment T02
ON T01.contact_id = T02.contact_id
INNER JOIN v_address_affiliation T03
ON T02.affiliation_id = T03.affiliation_id
INNER JOIN v_address T04
ON T03.address_id = T04.address_id
LEFT OUTER JOIN v_m_country T05
ON T04.country_Code = T05.country_code
WHERE T02.alignment_id = 1000004
AND T01.contact_id = 1000236952
ORDER BY T01.last_name ASC, T01.contact_id ASC
The above query takes 104.xx seconds. I fully analyzed all the tables and the number of rows are as follow:
v_contact -> 7490
v_address -> 10480
v_address_affiliation -> 10481
v_contact_alignment -> 1628151
v_m_country -> 231
I created index on v_contact(contact_id) but Oracle doesn't use that index and always perform full table scan. How can I tune the above statement?
Regards,
Chan

Answer 1

Hi,
I'm quite confusing now. I just omit the v_contact and the query returns 7378 rows in 7.9xx sec.
The query is
SELECT T04.address_line,T04.city,T04.state,T05.country_name
FROM v_contact_alignment T02
INNER JOIN v_address_affiliation T03
ON T02.affiliation_id = T03.affiliation_id
INNER JOIN v_address T04
ON T03.address_id = T04.address_id
LEFT OUTER JOIN v_m_country T05
ON T04.country_Code = T05.country_code
WHERE T02.alignment_id = 1000004 ORDER BY T04.address_line
The explain plan is as follow
SELECT STATEMENT 1347
SORT ORDER BY 1
HASH JOIN OUTER 1
HASH JOIN 1
HASH JOIN 1
TABLE ACCESS FULL CONTACT_ALIGNMENT 1
TABLE ACCESS FULL ADDRESS_AFFILIATION 2
TABLE ACCESS FULL ADDRESS 2
TABLE ACCESS FULL DN_HELP_ITEM 2
Even there are full table scan, it seems OK. But I don't understand why the full table scan for v_contact takes so much time as it only has 7xxx rows.
Any comment is welcome.
Regards,
Chan