Forcing to use index

Question

I have a query which is taking 2 minutes to respond. When I see the explain plan, it said for two tables it is doing the full table scan. So I tried forcing to use the index on the inner tables(xcm, detail) of the views(vw_xcm , vw_vw_detail). But it is still not using indexes when the query is running. Please let me know if I am forcing the indexes right.
Here is my code
SELECT x.customer_gci AS hdr_borrower_gci,
                x.industry_group_name AS hdr_borrower_sector,
                x.industry_subgroup_name AS hdr_borrower_industry,
                CAST (NULL AS number) AS hdr_incremental_fvo_amt,
                x.industry_subgroup_code AS hdr_industry_cd,
                x.industry_subgroup_name AS hdr_industry,
                CAST (NULL AS integer) AS hdr_cds_tenor,
                x.industry_group_code AS hdr_req_borrower_sector_cd,
                x.industry_subgroup_code AS hdr_req_borrower_industry_cd,
                x.customer_gci AS dtl_borrower_gci,
                x.customer_name AS dtl_company_name,
                (SELECT NVL (MAX (market_cap), 0)
                 FROM data_v2 kmv
                 WHERE     kmv.asof_date = (SELECT MAX (actual_data_date)
                                            FROM fvo_process_dtl dtl
                                            WHERE dtl.process_name = 'KMV')
                       AND kmv.spineid = x.spineid
                       AND kmv.market_cap <> 0)
                   AS dtl_marketcap,
                x.industry_subgroup_name AS dtl_industry,
                x.dtl_region,
                (SELECT SUM (NVL (notional, 0))
                 FROM vw_gcm
                 WHERE     datestamp = (SELECT MAX (datestamp)
                                        FROM vw_fvo_gcm_trade)
                       AND familygci = family_gci
                       AND rpt_product = 'LOAN'
                       AND rpt_risk_group = 'FVO')
                   AS dtl_current_fvo_amt,
                NULL AS dtl_trader_liquidity_cd,
                CAST (NULL AS number) AS dtl_manager_acceptable_amt,
                NULL AS dtl_lastused_date,
                NULL AS dtl_trader_comments,
                NULL AS dtl_manager_comments,
                CAST (NULL AS number) AS dtl_incremental_fvo_amt,
                x.industry_subgroup_code AS dtl_industry_code,
                x.spineid,
                (SELECT SUBSTR (MAX(TO_CHAR (ratingdate, 'YYYYMMDD')
                                    || iss.issuerrating),
                                9
                 FROM issuerrating iss
                 WHERE iss.ratingschemeid =
                          (SELECT rs.ratingschemeid
                           FROM ratingscheme rs
                           WHERE rs.ratingschemename = 'SNP')
                       AND iss.ratingtypeid = (SELECT rt.ratingtypeid
                                               FROM ratingtype rt
                                               WHERE rt.ratingtypecode = 'LT')
                       AND iss.ratingdate <= TRUNC (SYSDATE)
                       AND iss.issuerrating NOT IN
                                ('NR',
                                 'WR',
                                 'SD',
                                 'NM',
                                 'NRpi',
                                 'Rpi',
                                 'R',
                                 'SDpi')
                       AND iss.spineid = x.spineid)
                   AS dtl_snp_rating,
                (SELECT SUBSTR (MAX(TO_CHAR (ratingdate, 'YYYYMMDD')
                                    || iss.issuerrating),
                                9
                 FROM rating iss
                 WHERE iss.ratingschemeid =
                          (SELECT rs.ratingschemeid
                           FROM rating rs
                           WHERE rs.ratingschemename = 'MOODYS')
                       AND iss.ratingtypeid = (SELECT rt.ratingtypeid
                                               FROM ratingtype rt
                                               WHERE rt.ratingtypecode = 'LT')
                       AND iss.ratingdate <= TRUNC (SYSDATE)
                       AND iss.issuerrating NOT IN ('NR', 'WR', 'SD')
                       AND iss.spineid = x.spineid)
                   AS dtl_moodys_rating,
                risk_rating AS dtl_internal_rating
         FROM (SELECT /* + INDEX(xcm fvo_xcm_customer_ix3) INDEX(id fvo_ecris_d_industry_dtl_ix1)*/ xcm.customer_gci AS customer_gci,
                      xcm.customer_name AS customer_name,
                      TRIM (REPLACE (id.industry_group_name, '"', ' '))
                         AS industry_group_name,
                      id.industry_group_code,
                      TRIM (REPLACE (id.industry_subgroup_name, '"', ' '))
                         AS industry_subgroup_name,
                      id.industry_subgroup_code,
                      TRIM (REPLACE (id.industry_subgroup_name, '"', ' '))
                         AS dtl_industry,
                      (SELECT threealphacountrycode
                       FROM xcm_region_country_map r
                       WHERE     r.twoalphacountrycode = xcm.country_code
                             AND r.regioncode != 'INTL'
                             AND r.region IN ('North American', 'EMEA'))
                         AS dtl_region,
                      (SELECT spineid
                       FROM companymap cm
                       WHERE     cm.sourcereferenceid = 24
                             AND cm.sourcereferencevalue = xcm.customer_gci
                             AND cm.enddate IS NULL)
                         AS spineid,
                      xcm.family_gci AS family_gci,
                      xcm.risk_rating AS risk_rating
               FROM vw_xcm xcm,
                    (SELECT naics_code,
                            industry_group_name,
                            industry_group_code,
                            industry_subgroup_name,
                            industry_subgroup_code
                     FROM vw_detail
                     WHERE industry_subgroup_code IS NOT NULL) id
               WHERE     xcm.period = (SELECT MAX (period)
                                       FROM vw_xcm)
                     --                                  AND xcm.industry_detail_key =
                     --                                        id.industry_detail_key
                     AND xcm.naics_code = id.naics_code
                    AND TRIM (xcm.customer_gci) NOT LIKE 'S%') x
{code}                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               

Answer 1

Sometimes the cost-based optimizer will not take hints because it thinks it knows better. This is a matter of debate here on OTN, where some posters dogmatically assert that hints are instructions that must be followed. My experience is different. I have on rare occasions used perfectly good hints (usually INDEX) that the database simply refused to use.
Someone noted on a post a month or two ago that there may be a glitch with the CBO where it loses indexes when considering execution plans. This was based on a 10053 trace, which will show the different access paths considered during query evaluation.
Ultimately the CBO is deciding you query is more efficient not to use the indexes, even with your hint.
Looking again at your query I'll note that it is very complicated with inline views and more inline views. The CBO has trouble running multiple views efficiently - inline views, views of views, views joined to views - because views have no valid statistics associated with them. The choices the CBO makes based on views use defaults that are all but certain to be incorrect.
In particular, your index use for "id" makes no sense because it is an inline view. you could try using a global hint by pushing the hint inside the view, something like
INDEX(id.table_in_view fvo_ecris_d_industry_dtl_ix1)Unfortunately, the table inside the inline view id itself appears to be a view compliating this effort.
Try using the USE_NL hint instead of INDEX and see if that helps
Good luck