DBMS_LOB.INSTR Function makes mistake searching string on BLOB columns

Hi ,
i am using Oracle 8x. i have a table contains one BLOB column that store any type of file file (Word,Excel,PawerPoint etc). My application searhces data stored BLOB columns by using DBMS_LOB.INSTR function.But DBMS_LOG.INSTR funciton makes mistake searching BLOB columns and can not find the matching data.

 For example :

a Word file stored before and contains a string "THIS IS A TEST". MY SQL is ;

SELECT *
  FROM MYTABLE
WHERE DBMS_LOB.INSTR(MYCOLUNM,SYS.UTL_RAW.CAST_TO_RAW("THIS IS A TEST")) > 0
This SQL returns now row selected..

Please help me . What can i do ? or Am i wrong ?

Sincenerly
Adnan DURSUN Received on Mon Dec 03 2001 - 02:42:47 CST