Different results on 9i and 10g

[PAVB]

You are in troubles my fried, in my environment both versions of Oracle return the expected results...

I'm sorry but the closest versions I could get are 9.2.0.4.0 and 10.2.0.2.0

>>> Ora9i <<<

Connected to:
Oracle9i Enterprise Edition Release 9.2.0.4.0 - 64bit Production
With the Partitioning, OLAP and Oracle Data Mining options
JServer Release 9.2.0.4.0 - Production

SQL> set linesize 180
SQL> set pagesize 0
SQL> 
SQL> CREATE TABLE ADDRESS_TEST ( ADDR_ID NUMBER NOT NULL, ENT_ID NUMBER NOT NULL, ADDR1 VARCHAR2(255
), ADDR2 VARCHAR2(255), 
  2  ADDR3 VARCHAR2(255), CITY VARCHAR2(255), STATE VARCHAR2(255), COUNTRY VARCHAR2(100), 
  3  COUNTRY_CODE VARCHAR2(6), POSTAL_CODE VARCHAR2(20), SYS_DELETE_DT DATE) ;

Table created.

SQL> CREATE INDEX IX_ADDRESS_test_ADDR1 ON ADDRESS_TEST(UPPER(ADDR1)) ;

Index created.

SQL> CREATE INDEX IX_ADDR_test_CT_ST_CTRY ON ADDRESS_TEST(UPPER(CITY), UPPER(STATE), UPPER(COUNTRY))
 ;

Index created.

SQL> CREATE INDEX IX_ADDR_ENT ON ADDRESS_test(ENT_ID) REVERSE;

Index created.

SQL> ALTER TABLE ADDRESS_test ADD CONSTRAINT PK_ADDR_test PRIMARY KEY(addr_ID) USING INDEX;

Table altered.

SQL> Insert into ADDRESS_TEST values (1, 1,'123 Main street', null, null,'Las Vegas', 'nv', 'USA', '
us', '89119', null);

1 row created.

SQL> Insert into ADDRESS_TEST values (2, 1,'123 Main street', null, null,'Las Vegas', 'NV', 'USA', '
us', '89074', null);

1 row created.

SQL> SELECT  ENT_ID 
  2  FROM    ADDRESS_test 
  3  WHERE  (UPPER(CITY) LIKE upper('Las%') AND UPPER(STATE) = upper('nv') AND SYS_DELETE_DT IS NULL
 )
  4      OR (UPPER(POSTAL_CODE) = '99999' AND SYS_DELETE_DT IS NULL)
  5      OR (UPPER(POSTAL_CODE) = '99999' AND SYS_DELETE_DT IS NULL)
  6  ;
         1
         1

SQL> SELECT  ENT_ID 
  2  FROM    ADDRESS_test 
  3  WHERE  (UPPER(CITY) LIKE upper('Las%') AND UPPER(STATE) = upper('nv') AND SYS_DELETE_DT IS NULL
 )
  4      OR (UPPER(POSTAL_CODE) = '89119' AND SYS_DELETE_DT IS NULL)
  5      OR (UPPER(POSTAL_CODE) = '89074' AND SYS_DELETE_DT IS NULL)
  6  ;
         1
         1

SQL> SELECT  ENT_ID 
  2  FROM    ADDRESS_test 
  3  WHERE  (UPPER(CITY) LIKE upper('Las%') AND UPPER(STATE) = upper('nv') AND SYS_DELETE_DT IS NULL
 )
  4      OR (UPPER(POSTAL_CODE) = '89119' AND SYS_DELETE_DT IS NULL);
         1
         1

SQL>

>>> Ora10g <<<

Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.2.0 - 64bit Production
With the Partitioning, OLAP and Data Mining options

SQL> CREATE TABLE ADDRESS_TEST ( ADDR_ID NUMBER NOT NULL, ENT_ID NUMBER NOT NULL, ADDR1 VARCHAR2(255
), ADDR2 VARCHAR2(255), 
  2  ADDR3 VARCHAR2(255), CITY VARCHAR2(255), STATE VARCHAR2(255), COUNTRY VARCHAR2(100), 
  3  COUNTRY_CODE VARCHAR2(6), POSTAL_CODE VARCHAR2(20), SYS_DELETE_DT DATE) ;

Table created.

SQL> CREATE INDEX IX_ADDRESS_test_ADDR1 ON ADDRESS_TEST(UPPER(ADDR1)) ;

Index created.

SQL> CREATE INDEX IX_ADDR_test_CT_ST_CTRY ON ADDRESS_TEST(UPPER(CITY), UPPER(STATE), UPPER(COUNTRY))
 ;

Index created.

SQL> CREATE INDEX IX_ADDR_ENT ON ADDRESS_test(ENT_ID) REVERSE;

Index created.

SQL> ALTER TABLE ADDRESS_test ADD CONSTRAINT PK_ADDR_test PRIMARY KEY(addr_ID) USING INDEX;

Table altered.

SQL> Insert into ADDRESS_TEST values (1, 1,'123 Main street', null, null,'Las Vegas', 'nv', 'USA', '
us', '89119', null);

1 row created.

SQL> Insert into ADDRESS_TEST values (2, 1,'123 Main street', null, null,'Las Vegas', 'NV', 'USA', '
us', '89074', null);

1 row created.

SQL> SELECT  ENT_ID 
  2  FROM    ADDRESS_test 
  3  WHERE  (UPPER(CITY) LIKE upper('Las%') AND UPPER(STATE) = upper('nv') AND SYS_DELETE_DT IS NULL
 )
  4      OR (UPPER(POSTAL_CODE) = '99999' AND SYS_DELETE_DT IS NULL)
  5      OR (UPPER(POSTAL_CODE) = '99999' AND SYS_DELETE_DT IS NULL)
  6  ;

    ENT_ID
----------
         1
         1

SQL> SELECT  ENT_ID 
  2  FROM    ADDRESS_test 
  3  WHERE  (UPPER(CITY) LIKE upper('Las%') AND UPPER(STATE) = upper('nv') AND SYS_DELETE_DT IS NULL
 )
  4      OR (UPPER(POSTAL_CODE) = '89119' AND SYS_DELETE_DT IS NULL)
  5      OR (UPPER(POSTAL_CODE) = '89074' AND SYS_DELETE_DT IS NULL)
  6  ;

    ENT_ID
----------
         1
         1

SQL> SELECT  ENT_ID 
  2  FROM    ADDRESS_test 
  3  WHERE  (UPPER(CITY) LIKE upper('Las%') AND UPPER(STATE) = upper('nv') AND SYS_DELETE_DT IS NULL
 )
  4      OR (UPPER(POSTAL_CODE) = '89119' AND SYS_DELETE_DT IS NULL);

    ENT_ID
----------
         1
         1

I would open a TAR with Oracle including full listing of your case study showing the issue along side with event 10046/10053 traces.