Hugo Cardoso asks: Given a column name (word or small text) I want to choose from a set of column names the most seemed (if it is not equal). I'm thinking to use 'soundex' function, but I do not know if I can use it (and how use it) as a measured of proximity (choose the nearest) in the case of the function return it is not exactly the same.  I made some tests and it seems to me that the 'soundex' function it is not good for me (for example it is insensitive to the numbers).  I think that the solution for my problem is in utl_match built-in package. Is there any examples of using utl_match to compare strings?

From the Oracle documentation, we see these limits of the soundex function.

The soundex value always begins with the first letter in the input string. soundex only uses the first five consonants in the string to generate the return value. Only consonants are used to compute the numeric portion of the soundex value. Except for a possible leading vowel, all vowels are ignored. soundex is not case-sensitive. Upper- and lowercase letters return the same soundex value.

Using utl_match to compare strings

According to Oracle the utl_match utility is new in Oracle 10g release 2, and there is no documentation.  The undocumented utl_match package is used to compare the similarity of a target string and a examined string, embedded inside SQL. The utl_match procedure has four string compare functions:

edit_distance - This utl_edit function counts the number of character changes that are required to morph the target string into the examined string.

edit_distance_similarity - This utl_edit function returns the percentage of similarity between the target string and the examined string.

jaro_winkler - This utl_edit function is used to detect data entry errors by measuring the degree that the strings match.

jaro_winkler_similarity - This utl_edit function is similar to edit_distance_similiarity, computing the percentage of a string match.
 

This OTN thread shows some great examples of utl_match:

SCOTT@orcl_11g> -- ordering by utl_match.edit_distance:
SCOTT@orcl_11g> select z.*,  UTL_MATCH.EDIT_DISTANCE ('hilton hotel', LOWER (operator_name)) edit_dist
  2  from   operator z
  3  where contains (concat,'hilton hotel within {the_operator_name}',1 ) > 0
  4  ORDER BY edit_dist
  5  /

OPERATOR_ID OPERATOR_NAME                   EDIT_DIST
----------- ------------------------------ ----------
    1000084 Hilton Hotel                            0
    1005660 Hilton Hotel                            0
    1001397 HILTON HOTEL AIRPORT                    8
    1004356 Hilton Hotel/Avendra Eugene            15
    1001472 Hilton Hotel & Conference Ctr.         18

SCOTT@orcl_11g> -- ordering by utl_match.edit_distance_similarity:
SCOTT@orcl_11g> select z.*,  UTL_MATCH.EDIT_DISTANCE_SIMILARITY ('hilton hotel', LOWER (operator_name)) edit_dist_sim
  2  from   operator z
  3  where contains (concat,'hilton hotel within {the_operator_name}',1 ) > 0
  4  ORDER BY edit_dist_sim DESC
  5  /

OPERATOR_ID OPERATOR_NAME                  EDIT_DIST_SIM
----------- ------------------------------ -------------
    1000084 Hilton Hotel                             100
    1005660 Hilton Hotel                             100
    1001397 HILTON HOTEL AIRPORT                      60
    1004356 Hilton Hotel/Avendra Eugene               45
    1001472 Hilton Hotel & Conference Ctr.            40

SCOTT@orcl_11g> -- ordering without selecting the column:
SCOTT@orcl_11g> select * from operator z
  2  where contains (concat,'hilton hotel within {the_operator_name}',1 ) > 0
  3  ORDER BY UTL_MATCH.EDIT_DISTANCE ('hilton hotel', LOWER (operator_name))
  4  /

OPERATOR_ID OPERATOR_NAME
----------- ------------------------------
    1000084 Hilton Hotel
    1005660 Hilton Hotel
    1001397 HILTON HOTEL AIRPORT
    1004356 Hilton Hotel/Avendra Eugene
    1001472 Hilton Hotel & Conference Ctr.

SCOTT@orcl_11g> select * from operator z
  2  where contains (concat,'hilton hotel within {the_operator_name}',1 ) > 0
  3  ORDER BY UTL_MATCH.EDIT_DISTANCE_SIMILARITY ('hilton hotel', LOWER (operator_name)) DESC
  4  /

OPERATOR_ID OPERATOR_NAME
----------- ------------------------------
    1000084 Hilton Hotel
    1005660 Hilton Hotel
    1001397 HILTON HOTEL AIRPORT
    1004356 Hilton Hotel/Avendra Eugene
    1001472 Hilton Hotel & Conference Ctr.