Ok, thank you, but hint for index does not work yet. Object report.v5103f_fact_value is view, so I rewrite the hint as follows: /* + INDEX(fv.r T5103F_FACT_VALUE_INDEX8) */. The "fv" is alias for view and "r" is alias for table in view definition. But it still does not work. I didn't find any reason, why the optimizer ignore this hint. I partially solve the problem with group by described above (I simplified query and change the index definition). But I have problem with field from another table, which causes that the optimizer don't use the index. Example: Code (SQL): ALTER SYSTEM FLUSH BUFFER_CACHE; ALTER SYSTEM FLUSH SHARED_POOL; SET autotrace ON; SELECT /* + INDEX(fv.r T5103F_FACT_VALUE_INDEX8) */ fv.fisc_year, fv.period, fv.facttype_id, fv.key_figure FROM report.v5103f_fact_value fv INNER JOIN report.v0000d_company_inform c ON c.comp_code = fv.comp_code AND c.busidiv = fv.busidiv INNER JOIN dwmeta.v5103d_kf_user_auth a ON (c.comp_code=a.comp_code OR a.comp_code IN('all','sum')) -- and a.user_id = 'AAA' WHERE (fisc_year,period) IN (('2013','005'),('2013','00'),('2013','012')) AND ((version_id=5 AND ((facttype_id!=1) OR (facttype_id=1 AND (period!='012' OR (period='012' AND version_id=5))) ))) --and a.user_id='AAA' GROUP BY fv.fisc_year, fv.period, fv.facttype_id, fv.key_figure ; SET autotrace OFF; Index T5103F_FACT_VALUE_INDEX8 have these columns (in this order): (FISC_YEAR, PERIOD, FACTTYPE_ID, KEY_FIGURE, VERSION_ID, COMP_CODE, BUSIDIV) If I uncomment condition "and a.user_id = 'AAA'", optimizer does't use index T5103F_FACT_VALUE_INDEX8 but use index for primary key (BUSIDIV, COMP_CODE, KEY_FIGURE, FISC_YEAR, PERIOD, VERSION_ID, FACTTYPE_ID, QUELLE). It does not matter if is in FROM clause, or in WHERE clause. I need to find the reason, why the condition on table dwmeta.v5103d_kf_user_auth affects to using index on table T5103F_FACT_VALUE. I really don't understand it Thank you for some help.