How do i re-write

Question

Hi !
If i were to re-write this query with joins, how would i do it ? Anyone ?
DELETE
FROM XCM_VO01_VEHOFINT VOIA
WHERE VOIA.COUNTRY_ISO3_C = 'DEU'
AND VOIA.CUST_BRAND_C = 'F'
AND VOIA.CUCON_CNTCT_ST_S > to_date('2005-10-24', 'YYYY-MM-DD')
AND EXISTS
(SELECT *
FROM XCM_CU10_CONTACT CU10
WHERE CU10.COUNTRY_ISO3_C = VOIA.COUNTRY_ISO3_C
AND CU10.CUST_CUSTOMER_R = VOIA.CUST_CUSTOMER_R
AND CU10.CUST_BRAND_C = VOIA.CUST_BRAND_C
AND CU10.CUCON_CNTCT_ST_S = VOIA.CUCON_CNTCT_ST_S
AND CU10.CUCON_CNTCT_R = VOIA.CUCON_CNTCT_R
AND CU10.COUNTRY_ISO3_C = 'DEU'
AND CU10.CUST_BRAND_C = 'F'
AND CU10.CUCON_TREAT_TYP_C = 'TDN'
AND CU10.CUCON_VALUE_TRK_C = 'FDEU900008'
AND CU10.CUCON_CNTCT_ST_S > to_date('2005-10-24', 'YYYY-MM-DD')
AND CU10.CUCON_CNTCT_R <>
(SELECT MIN(CUCON_CNTCT_R) FROM XCM_CU10_CONTACT CU10A
WHERE CU10A.COUNTRY_ISO3_C = CU10.COUNTRY_ISO3_C
AND CU10A.CUST_CUSTOMER_R = CU10.CUST_CUSTOMER_R
AND CU10A.CUST_BRAND_C = CU10.CUST_BRAND_C
AND CU10A.CUCON_CNTCT_ST_S = CU10.CUCON_CNTCT_ST_S
AND CU10A.CUCON_TREAT_TYP_C = 'TDN'
AND CU10A.CUCON_VALUE_TRK_C = 'FDEU900008')
AND
( EXISTS
(SELECT * FROM
XCM_CU10_CONTACT CU10B
WHERE CU10B.COUNTRY_ISO3_C = CU10.COUNTRY_ISO3_C
AND CU10B.CUST_CUSTOMER_R = CU10.CUST_CUSTOMER_R
AND CU10B.CUCON_CNTCT_R != CU10.CUCON_CNTCT_R
AND CU10B.CUST_BRAND_C = CU10.CUST_BRAND_C
AND CU10B.CUCON_CNTCT_ST_S = CU10.CUCON_CNTCT_ST_S
AND CU10B.CUCON_TREAT_TYP_C = 'TDN'
AND CU10B.CUCON_VALUE_TRK_C = 'FDEU900008')));

Answer 1

Eric:
It doesn't really matter what you select, because exists doesn't really return anything. Oracle will use the fastest access path possible to find a record. As soon as it finds a record, it stops and EXISTS becomes true.
SQL> CREATE TABLE t AS
  2  SELECT object_id, owner, object_name
  3  FROM all_objects;
Table created.
SQL> CREATE TABLE t1 AS SELECT * FROM all_objects;
Table created.
SQL> ALTER TABLE t ADD CONSTRAINT t_pk PRIMARY KEY (object_id);
Table altered.
SQL> ANALYZE TABLE t COMPUTE STATISTICS FOR TABLE FOR ALL INDEXES
  2  FOR ALL INDEXED COLUMNS;
Table analyzed.
SQL> set autot trace explain
SQL> SELECT * FROM t1
  2  WHERE EXISTS (SELECT owner FROM t
  3                WHERE t1.object_id = t.object_id);
Execution Plan
   0      SELECT STATEMENT Optimizer=CHOOSE (Cost=11 Card=14299 Bytes=1887468)
   1    0   NESTED LOOPS (SEMI) (Cost=11 Card=14299 Bytes=1887468)
   2    1     TABLE ACCESS (FULL) OF 'T1' (Cost=10 Card=18444 Bytes=2360832)
   3    1     INDEX (UNIQUE SCAN) OF 'T_PK' (UNIQUE)Even though I am "selecting" owner from t, there is no table access because the existence check can be satisfied by using the PK.
HTH
John