SELECT FIELD1,FIELD2,FIELD3 FROM TABLE_1;

SELECT FIELD1,FIELD2,FIELD3 FROM TABLE_1 T1 
WHERE EXISTS 
(SELECT /*+ INDEX_FFS(T2) */ T2.FIELD1
  FROM T2 WHERE T1.ROWID = T2.ROWID AND 
       T2.FIELD1 IS NOT NULL);

SELECT STATEMENT, GOAL = CHOOSE			Cost=22172	Cardinality=1	Bytes=136
 FILTER					
  TABLE ACCESS BY INDEX ROWID	Object owner=OWNER	Object name=tab_8	Cost=3	Cardinality=1	Bytes=13
   NESTED LOOPS			Cost=22172	Cardinality=1	Bytes=136
    NESTED LOOPS			Cost=22169	Cardinality=1	Bytes=123
     NESTED LOOPS			Cost=22167	Cardinality=1	Bytes=115
      NESTED LOOPS			Cost=21480	Cardinality=229	Bytes=22442
       NESTED LOOPS			Cost=14238	Cardinality=3621	Bytes=177429
        [B]HASH JOIN[/B]			Cost=2820	Cardinality=3806	Bytes=49478
         TABLE ACCESS BY GLOBAL INDEX ROWID	Object owner=OWNER	Object name=tab_1	Cost=10	Cardinality=6492	Bytes=45444
          INDEX RANGE SCAN	Object owner=OWNER	Object name=tab_1_idx	Cost=2	Cardinality=6	
         INDEX FAST FULL SCAN	Object owner=OWNER	Object name=tab_2_PK	Cost=2073	Cardinality=22025937	Bytes=132155622
        TABLE ACCESS BY INDEX ROWID	Object owner=OWNER	Object name=tab_3_pk	Cost=3	Cardinality=1	Bytes=36
         INDEX RANGE SCAN	Object owner=OWNER	Object name=tab_3_idx	Cost=2	Cardinality=1	
       TABLE ACCESS BY INDEX ROWID	Object owner=OWNER	Object name=tab_4	Cost=2	Cardinality=1	Bytes=49
        INDEX UNIQUE SCAN	Object owner=OWNER	Object name=tab_4_pk	Cost=1	Cardinality=1	
      TABLE ACCESS BY INDEX ROWID	Object owner=OWNER	Object name=tab_5	Cost=3	Cardinality=1	Bytes=17
       INDEX RANGE SCAN	Object owner=OWNER	Object name=tab_5_idx	Cost=2	Cardinality=1	
     TABLE ACCESS BY INDEX ROWID	Object owner=OWNER	Object name=tab_6	Cost=2	Cardinality=1	Bytes=8
      INDEX UNIQUE SCAN	Object owner=OWNER	Object name=tab_6_pk	Cost=1	Cardinality=1	
    INDEX RANGE SCAN	Object owner=OWNER	Object name=tab_7_idx	Cost=2	Cardinality=1	

SELECT STATEMENT, GOAL = CHOOSE			Cost=1298	Cardinality=1	Bytes=143
 FILTER					
  TABLE ACCESS BY INDEX ROWID	Object owner=OWNER	Object name=tab_8	Cost=3	Cardinality=1	Bytes=13
   NESTED LOOPS			Cost=1298	Cardinality=1	Bytes=143
    NESTED LOOPS			Cost=1295	Cardinality=1	Bytes=130
     NESTED LOOPS			Cost=1293	Cardinality=1	Bytes=122
      NESTED LOOPS			Cost=1260	Cardinality=11	Bytes=1155
       NESTED LOOPS			Cost=898	Cardinality=181	Bytes=10136
        [B]NESTED LOOPS[/B]			Cost=328	Cardinality=190	Bytes=3800
         TABLE ACCESS BY GLOBAL INDEX ROWID	Object owner=OWNER	Object name=tab_1	Cost=3	Cardinality=325	Bytes=4550
          INDEX RANGE SCAN	Object owner=OWNER	Object name=tab_1_idx	Cost=2	Cardinality=8486	
         INDEX UNIQUE SCAN	Object owner=OWNER	Object name=tab_2_PK	Cost=1	Cardinality=1	Bytes=6
        TABLE ACCESS BY INDEX ROWID	Object owner=OWNER	Object name=tab_3_pk	Cost=3	Cardinality=1	Bytes=36
         INDEX RANGE SCAN	Object owner=OWNER	Object name=tab_3_idx	Cost=2	Cardinality=1	
       TABLE ACCESS BY INDEX ROWID	Object owner=OWNER	Object name=tab_4	Cost=2	Cardinality=1	Bytes=49
        INDEX UNIQUE SCAN	Object owner=OWNER	Object name=tab_4_pk	Cost=1	Cardinality=1	
      TABLE ACCESS BY INDEX ROWID	Object owner=OWNER	Object name=tab_5	Cost=3	Cardinality=1	Bytes=17
       INDEX RANGE SCAN	Object owner=OWNER	Object name=tab_5_idx	Cost=2	Cardinality=1	
     TABLE ACCESS BY INDEX ROWID	Object owner=OWNER	Object name=tab_6	Cost=2	Cardinality=1	Bytes=8
      INDEX UNIQUE SCAN	Object owner=OWNER	Object name=tab_6_pk	Cost=1	Cardinality=1	
    INDEX RANGE SCAN	Object owner=OWNER	Object name=tab_7_idx	Cost=2	Cardinality=1	

select fields...
  from tab_1 act
    join tab_2 os on act.id_os = os.id
    join tab_3 c on c.id_os = os.id
    join tab_5 l on l.id_os = c.id_os and l.nr_lucrare = c.nr_lucrare
    join tab_8 a on a.id_lprodso = l.id
    join tab_4 cer on cer.id = c.id_cerere
    join tab_6 cl on cl.id = cer.id_client
  where cer.cod_tip_cerere = 'XXX'
    and act.respins = 'Y'
    and cer.validata = 'Y'
    and act.respins_data between (sysdate - 7) and sysdate 
    and act.rowid = act.rowid