--
-- Start by creating our table
--
richardh=> create table foo (a serial, b text, c timestamp);
NOTICE:  CREATE TABLE will create implicit sequence 'foo_a_seq' for SERIAL column 'foo.a'
NOTICE:  CREATE TABLE/UNIQUE will create implicit index 'foo_a_key' for table 'foo'
CREATE

--
-- Now import the lastchg module (you might want to use the full path)
--
richardh=> \i lastchange.sql
CREATE
CREATE

--
-- Create insert/update trigger
--
richardh=> select lastchg_addto('foo','c');
      lastchg_addto
-------------------------
 Created lastchg trigger
(1 row)

--
-- Insert some data
--
richardh=> insert into foo (b) values ('aaa');
INSERT 217867 1
richardh=> insert into foo (b) values ('bbb');
INSERT 217868 1
richardh=> insert into foo (b) values ('ccc');
INSERT 217869 1

richardh=> select * from foo;
 a |  b  |           c
---+-----+------------------------
 1 | aaa | 2001-02-08 09:33:35+00
 2 | bbb | 2001-02-08 09:33:38+00
 3 | ccc | 2001-02-08 09:33:40+00
(3 rows)

--
-- Update some data
--
richardh=> update foo set b='xxx';
UPDATE 3
richardh=> select * from foo;
 a |  b  |           c
---+-----+------------------------
 1 | xxx | 2001-02-08 09:34:41+00
 2 | xxx | 2001-02-08 09:34:41+00
 3 | xxx | 2001-02-08 09:34:41+00
(3 rows)

--
-- Remove the triggers
--
richardh=> select lastchg_remove('foo','c');
     lastchg_remove
-------------------------
 Removed lastchg trigger
(1 row)

--
-- Timestamp shouldn't update now
--
richardh=> update foo set b='yyy';
UPDATE 3
richardh=> select * from foo;
 a |  b  |           c
---+-----+------------------------
 1 | yyy | 2001-02-08 09:34:41+00
 2 | yyy | 2001-02-08 09:34:41+00
 3 | yyy | 2001-02-08 09:34:41+00
(3 rows)