complex_abs_cmp(Complex*a,Complex*b)

{

doubleamag=Mag(a),bmag=Mag(b);

if (a<b)

if (amag<bmag)

return-1;

elseif (a>b)

elseif (amag>bmag)

return1;

return0;

--

-- complex.sql-

-- This file shows how to create a new user-defined type and how to

-- usethem.

-- usethis new type.

--

--

-- Copyright (c) 1994, Regents of the University of California

--

-- $Id: complex.source,v 1.1.1.1 1996/07/09 06:22:34 scrappy Exp $

-- $Id: complex.source,v 1.2 1996/12/28 02:22:07 momjian Exp $

--

---------------------------------------------------------------------------

-----------------------------

-- Creating aggregate functions

--you can also define aggregate functions. The syntax issome what

--you can also define aggregate functions. The syntax issomewhat

--cryptic but the idea is to express the aggregate in terms of state

--transition functions.

-----------------------------

-------------------------------------------------------------------------------

-- ATTENTION! ATTENTION! ATTENTION! --

-- YOU MAY SKIP THE SECTION BELOW ON INTERFACING WITHINDICIES. YOU DON'T --

-- NEED THE FOLLOWING IF YOU DON'T USEINDICIES WITH NEW DATA TYPES. --

-- YOU MAY SKIP THE SECTION BELOW ON INTERFACING WITHINDICES. YOU DON'T --

-- NEED THE FOLLOWING IF YOU DON'T USEINDICES WITH NEW DATA TYPES. --

-------------------------------------------------------------------------------

SELECT 'READ ABOVE!' AS STOP;

and proname = 'complex_abs_cmp';

-- now, we can define a btree index on complex types. First, let's populate

-- the table (THIS DOESN'T ACTUALLY WORK. YOU NEED MANY MORE TUPLES.)

-- the table. Note that postgres needs many more tuples to start using the

-- btree index during selects.

INSERT INTO test_complex VALUES ('(56.0,-22.5)', '(-43.2,-0.07)')

INSERT INTO test_complex VALUES ('(-91.9,33.6)', '(8.6,3.0)');

SELECT * from test_complex where a = '(56.0,-22.5)';

SELECT * from test_complex where a < '(56.0,-22.5)';

SELECT * from test_complex where a > '(56.0,-22.5)';

SELECT * from test_complex where a > '(56.0,-22.5)';