Oracle Function Lexical Match

Finds a match if every word in one string is in the other string:

CREATE OR REPLACE FUNCTION LEXICAL_MATCH (STR1   IN VARCHAR2,
                                                 STR2   IN VARCHAR2)
   RETURN NUMBER
IS
   THE_RESULT    NUMBER := 0;
   POS_SPACE     NUMBER;
   POS_WORD      NUMBER;
   SINGLE_WORD   VARCHAR2 (250);
   -- NOT CASE SENSITIVE COMPARE
   STRING1       VARCHAR2 (250) := UPPER (STR1);
   STRING2       VARCHAR2 (250) := UPPER (STR2);
BEGIN
   -- TEST IF ALREADY A MATCH
   IF STRING1 = STRING2
   THEN
      RETURN (1);
   ELSE
      -- TEST IF THERE IS A SPACE IN THE STRING
      POS_SPACE := INSTR (STRING1, ' ');

      IF POS_SPACE <> 0
      THEN
         LOOP
            SINGLE_WORD := SUBSTR (STRING1, 1, POS_SPACE - 1);
            STRING1 := SUBSTR (STRING1, POS_SPACE + 1);
            POS_WORD := INSTR (STRING2, SINGLE_WORD);

            IF POS_WORD = 0
            THEN
               THE_RESULT := 0;
            ELSE
               THE_RESULT := 1;
               -- REMOVE WORD FROM STRING2 - 3 SCENARIOS: WORD AT THE FRONT, MIDDLE, OR END - DON'T WORRY ABOUT REMOVING SPACES IN STRING2  
               STRING2 :=
                  SUBSTR (STRING2, 1, POS_WORD - 1) || SUBSTR (STRING2, POS_WORD + LENGTH (SINGLE_WORD) );
            END IF;

            -- REPEAT IN THE CASE OF 3 OR MORE WORDS
            POS_SPACE := INSTR (STRING1, ' ');

            EXIT WHEN POS_SPACE = 0 OR THE_RESULT = 0;
         END LOOP;

         IF TRIM(STRING1) <> TRIM(STRING2) -- CHECK IF STRING2 STILL HAS MORE WORDS LEFT, IF NOT THE REMAINING WORDS SHOULD MATCH
         THEN
            THE_RESULT := 0;
         END IF;

         RETURN (THE_RESULT);
      ELSE
         RETURN (0);                                 -- NO MATCH AND NO SPACES
      END IF;
   END IF;
END;
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