metaphone \

metaphone -

Improved Soundex function

by Joel Burton <jburton@scw.org>

subdir = contrib/metaphone

top_builddir = ../..

include $(top_builddir)/src/Makefile.global

NAME := metaphone

SONAME := $(NAME)$(DLSUFFIX)

override CPPFLAGS += -I$(srcdir)

override CFLAGS += $(CFLAGS_SL)

all: $(SONAME) $(NAME).sql

$(NAME).sql: $(NAME).sql.in

sed 's,@MODULE_FILENAME@,$(libdir)/contrib/$(SONAME),g' $< >$@

install: all installdirs

$(INSTALL_SHLIB) $(SONAME) $(libdir)/contrib

$(INSTALL_DATA) $(NAME).sql $(datadir)/contrib

$(INSTALL_DATA) README.$(NAME) $(docdir)/contrib

installdirs:

$(mkinstalldirs) $(libdir)/contrib $(datadir)/contrib $(docdir)/contrib

uninstall:

rm -f $(libdir)/contrib/$(SONAME) $(datadir)/contrib/$(NAME).sql $(docdir)/contrib/README.$(NAME)

clean distclean maintainer-clean:

rm -f $(SONAME) $(NAME).o $(NAME).sql

depend dep:

$(CC) -MM -MG $(CFLAGS) *.c > depend

ifeq (depend,$(wildcard depend))

include depend

This directory contains a module that implements the "Metaphone" code as

a PostgreSQL user-defined function. The Metaphone system is a method of

matching similar sounding names (or any words) to the same code.

Metaphone was invented by Lawrence Philips as an improvement to the popular

name-hashing routine, Soundex.

This metaphone code is from Michael Kuhn, and is detailed at

http://aspell.sourceforge.net/metaphone/metaphone-kuhn.txt

Code for this (including this help file!) was liberally borrowed from

the soundex() module for PostgreSQL.

There are two functions:

metaphone(text) : returns hash of a name

metaphone(text,int) : returns hash (maximum length of int) of name

---

To install it, first configure the main source tree, then run make;

make install in this directory. Finally, load the function definition

with psql:

psql -f PREFIX/share/contrib/metaphone.sql

The following are some usage examples:

SELECT text_metaphone('hello world!');

SELECT text_metaphone('hello world!', 4);

CREATE TABLE s (nm text)\g

insert into s values ('john')\g

insert into s values ('joan')\g

insert into s values ('wobbly')\g

select * from s

where text_metaphone(nm) = text_metaphone('john')\g

select nm from s a, s b

where text_metaphone(a.nm) = text_metaphone(b.nm)

and a.oid <> b.oid\g

CREATE FUNCTION text_mp_eq(text, text) RETURNS bool AS

'select text_metaphone($1) = text_metaphone($2)'

LANGUAGE 'sql'\g

CREATE FUNCTION text_mp_lt(text,text) RETURNS bool AS

'select text_metaphone($1) < text_metaphone($2)'

LANGUAGE 'sql'\g

CREATE FUNCTION text_mp_gt(text,text) RETURNS bool AS

'select text_metaphone($1) > text_metaphone($2)'

LANGUAGE 'sql';

CREATE FUNCTION text_mp_le(text,text) RETURNS bool AS

'select text_metaphone($1) <= text_metaphone($2)'

LANGUAGE 'sql';

CREATE FUNCTION text_mp_ge(text,text) RETURNS bool AS

'select text_metaphone($1) >= text_metaphone($2)'

LANGUAGE 'sql';

CREATE FUNCTION text_mp_ne(text,text) RETURNS bool AS

'select text_metaphone($1) <> text_metaphone($2)'

LANGUAGE 'sql';

DROP OPERATOR #= (text,text)\g

CREATE OPERATOR #= (leftarg=text, rightarg=text, procedure=text_mp_eq,

commutator=text_mp_eq)\g

SELECT *

FROM s

WHERE text_mp_eq(nm,'pillsbury')\g

SELECT *

from s

where s.nm #= 'pillsbury';