Soundex

I found a booklet called Introduction to SQL Version 1.0, printed in 1985 and 1989. It was written by a certain Lawrence Ellison and described a function called SOUNDEX, which I had never heard of before, so I tried it out on an Oracle 9 database.

SOUNDEX represents the sound of a word by a 4 character alphanumeric code. Words which sound alike should have the same code. This allows you to select rows containing data with a particular sound. Sometimes it works:

 

SQL> select soundex('STEWART') from dual;

 

SOUN

----

S363

 

SQL> select soundex('STUART') from dual;

 

SOUN

----

S363

 

SQL> select soundex('BORED') from dual;

 

SOUN

----

B630

 

SQL> select soundex('BOARD') from dual;

 

SOUN

----

B630

 

SQL>

 

But sometimes it gives words, which sound the same, different codes:

 

SQL> select soundex('WITCH') from dual;

 

SOUN

----

W320

 

SQL> select soundex('WHICH') from dual;

 

SOUN

----

W200

 

SQL>

 

And sometimes it gives words, which sound different, the same code:

 

SQL> select soundex('FLOOR') from dual;

 

SOUN

----

F460

 

SQL> select soundex('FLOUR') from dual;

 

SOUN

----

F460

 

SQL>