Simple query help in plsql - help

Question

oracle version : 10gR2
indexes are created on each column, is there anyway to make them used while searching for the records rewriting the following query to test given data in any case (lower ,upper)...
SELECT * FROM TX_USERS
WHERE userid like decode( UPPER('Md'),null,userid, UPPER( 'MD')||'%' ) and
first_name like decode(UPPER('Na'),null, first_name, UPPER( 'NA')||'%' ) AND
LAST_name like decode(('Ra'),null, LAST_name, UPPER('RA')||'%' )
-- list goes on..
UPPER('Md') -- is the input values comes from form.. for example i_userid.. this query works fine .. is there anyway of getting indices used without using functional based indexing when we rewrite query like shown below??? input parameter valeus can be anything and table column values can be anything i.e. anycase (upper or lower or mix of both)..
actual code would be
upper(userid) like decode( UPPER(i_userid),null,userid, UPPER( i_userid)||'%' ) and
upper(first_name) like decode(UPPER(i_first_name),null, first_name, UPPER( i_firstname)||'%' )
if we put upper(userid) then index not used ..........anyway of rewriting using it or any other technique... or any other new way

Answer 1

No, its not working... see the below..
create table test5 as select owner, object_name, subobject_name, object_type from all_objects;
create unique index test5_i5 on test5 (owner, object_name, subobject_name, object_type);
select * from test5 where owner like 'SCOTT' AND OBJECT_NAME LIKE 'EMP';
INDEX RANGE SCAN| TEST5_I5 | 4 | 248 | 1 (0)| 00:00:01 |
but when i use
select * from test5 where UPPER(OWNER) LIKE 'SCOTT%' AND UPPER(OBJECT_NAME) LIKE 'EMP%';
TABLE ACCESS FULL| TEST5 | 3 | 186 | 65 (5)| 00:00:01 |
i know it goes to full scan, i want to know is there any other way to make index used .. without using functional based indx...
the reason is user can search any one of the column data and data is mixed case in table columns and/or conditions specified in query..
.. any help...
not sure how to use 'NLS_SORT=BINARY_CI' on multicolumn index and enable index used in search operation.. ANY OTHER WAY OF DOING THIS...
requirements is
mixed (lower,upper) data stored in db columns and mixed case data searched, 5 columns specified in where condition, data may be provided in search conditon to one or two or to all 5 columns in mixed case... matching records need to be returned.. suggest a good way of doing this... thnx