1) http://pgfoundry.org/projects/tablelog/
2) tar zxvf table_log-0.4.4.tar.gz
3) cd table_log-0.4.4/
4) vim README.table_log
5) Install
	5.1) yum install -y postgresql-devel.x86_64
	5.2) make USE_PGXS=1
	5.3) su
	5.4) make USE_PGXS=1 install
6) Instalar en la db
	6.1) CREATE LANGUAGE plpgsql;
	6.2) Crear funciones:

CREATE FUNCTION "table_log" ()
    RETURNS trigger
    AS '$libdir/table_log', 'table_log' LANGUAGE 'C';
CREATE FUNCTION "table_log_restore_table" (VARCHAR, VARCHAR, CHAR, CHAR, CHAR, TIMESTAMPTZ, CHAR, INT, INT)
    RETURNS VARCHAR
    AS '$libdir/table_log', 'table_log_restore_table' LANGUAGE 'C';
CREATE FUNCTION "table_log_restore_table" (VARCHAR, VARCHAR, CHAR, CHAR, CHAR, TIMESTAMPTZ, CHAR, INT)
    RETURNS VARCHAR
    AS '$libdir/table_log', 'table_log_restore_table' LANGUAGE 'C';
CREATE FUNCTION "table_log_restore_table" (VARCHAR, VARCHAR, CHAR, CHAR, CHAR, TIMESTAMPTZ, CHAR)
    RETURNS VARCHAR
    AS '$libdir/table_log', 'table_log_restore_table' LANGUAGE 'C';
CREATE FUNCTION "table_log_restore_table" (VARCHAR, VARCHAR, CHAR, CHAR, CHAR, TIMESTAMPTZ)
    RETURNS VARCHAR
    AS '$libdir/table_log', 'table_log_restore_table' LANGUAGE 'C';

	6.3) psql -U postgres milog < table_log_init.sql
7) Probar
	7.1) create table foo(id serial primary key, nombre character varying(32) unique, credito numeric not null default 0);
	7.2) select table_log_init(3, 'foo');
	7.3) insert into foo values(default,'mi nombre',100);
	7.4) insert into foo values(default,'postgresql',100);
	7.5) insert into foo values(default,'satan es la cumbia',100);
	7.6) update foo set nombre = upper(nombre);
	7.7) select * from foo_log;