SELECT * 
FROM   address 
WHERE  address1 = 'a' 
       AND address2 = 'b' 
       AND address3 = 'c' 
       AND city = 'xy' 
       AND state IS NULL 
       AND county IS NULL 
       AND country = 'IN' 
       AND postcode = '45';  

SQL> 
SQL> drop table address purge;

Table dropped.

SQL> 
SQL> CREATE TABLE address
  2    (
  3  	  address_id VARCHAR2 (40) NOT NULL,
  4  	  address1   VARCHAR2 (40) NOT NULL,
  5  	  address2   VARCHAR2 (40) NULL,
  6  	  address3   VARCHAR2 (40) NULL,
  7  	  city	     VARCHAR2(50) NOT NULL,
  8  	  state      VARCHAR2(50) NULL,
  9  	  county     VARCHAR2(50) NULL,
 10  	  country    VARCHAR2(50) NULL,
 11  	  postcode   VARCHAR2(10) NOT NULL,
 12  	  flag	     VARCHAR2(5) NULL,
 13  	  TYPE	     VARCHAR2(30) NULL,
 14  	  CONSTRAINT address_id_pk PRIMARY KEY( address_id)
 15    );

Table created.

SQL> 
SQL> INSERT INTO address
  2  		 (address_id,
  3  		  address1,
  4  		  address2,
  5  		  address3,
  6  		  city,
  7  		  state,
  8  		  county,
  9  		  country,
 10  		  postcode,
 11  		  flag,
 12  		  TYPE)
 13  VALUES	 ( '1',
 14  		  'a',
 15  		  'b',
 16  		  'c',
 17  		  'xy',
 18  		  NULL,
 19  		  NULL,
 20  		  'IN',
 21  		  '45',
 22  		  NULL,
 23  		  NULL);

1 row created.

SQL> 
SQL> INSERT INTO address
  2  		 (address_id,
  3  		  address1,
  4  		  address2,
  5  		  address3,
  6  		  city,
  7  		  state,
  8  		  county,
  9  		  country,
 10  		  postcode,
 11  		  flag,
 12  		  TYPE)
 13  VALUES	 ( '2',
 14  		  'b',
 15  		  'b',
 16  		  'c',
 17  		  'xy',
 18  		  NULL,
 19  		  NULL,
 20  		  'IN',
 21  		  '45',
 22  		  NULL,
 23  		  NULL);

1 row created.

SQL> 
SQL> INSERT INTO address
  2  		 (address_id,
  3  		  address1,
  4  		  address2,
  5  		  address3,
  6  		  city,
  7  		  state,
  8  		  county,
  9  		  country,
 10  		  postcode,
 11  		  flag,
 12  		  TYPE)
 13  VALUES	 ( '3',
 14  		  'c',
 15  		  'b',
 16  		  'c',
 17  		  'xy',
 18  		  NULL,
 19  		  NULL,
 20  		  'IN',
 21  		  '45',
 22  		  NULL,
 23  		  NULL);

1 row created.

SQL> 
SQL> COMMIT;

Commit complete.

SQL> 
SQL> SELECT *
  2  FROM   address
  3  WHERE  address1 = 'a'
  4  	    AND address2 = 'b'
  5  	    AND address3 = 'c'
  6  	    AND city = 'xy'
  7  	    AND state IS NULL
  8  	    AND county IS NULL
  9  	    AND country = 'IN'
 10  	    AND postcode = '45';

PLAN_TABLE_OUTPUT
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Plan hash value: 948192439

-----------------------------------------------------------------------------
| Id  | Operation         | Name    | Rows  | Bytes | Cost (%CPU)| Time     |
-----------------------------------------------------------------------------
|   0 | SELECT STATEMENT  |         |     1 |   224 |     3   (0)| 00:00:01 |
|*  1 |  TABLE ACCESS FULL| ADDRESS |     1 |   224 |     3   (0)| 00:00:01 |
-----------------------------------------------------------------------------

Predicate Information (identified by operation id):
---------------------------------------------------

PLAN_TABLE_OUTPUT
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

   1 - filter("STATE" IS NULL AND "COUNTY" IS NULL AND "ADDRESS1"='a'
              AND "ADDRESS2"='b' AND "ADDRESS3"='c' AND "CITY"='xy' AND
              "COUNTRY"='IN' AND "POSTCODE"='45')

Note
-----
   - dynamic sampling used for this statement

19 rows selected.

   1 - filter("STATE" IS NULL AND "COUNTY" IS NULL AND "ADDRESS1"='a'
              AND "ADDRESS2"='b' AND "ADDRESS3"='c' AND "CITY"='xy' AND
              "COUNTRY"='IN' AND "POSTCODE"='45')