Create a table to store changes from any of your tables in a log table.

change_log.sql

--
-- Create a table in your CartoDB editor called 'version_control'
-- Run the following SQL in your editor to create the needed columns
--

ALTER TABLE version_control ADD COLUMN data json;
ALTER TABLE version_control ADD COLUMN source_id integer;
ALTER TABLE version_control ADD COLUMN table_name text;
ALTER TABLE version_control ADD COLUMN tg_op text;

--
-- Add the following function in your CartoDB account from any SQL interface
--

CREATE OR REPLACE FUNCTION axh_version_control() RETURNS TRIGGER AS $$
    BEGIN
        IF (TG_OP = 'DELETE') THEN
            INSERT INTO version_control(the_geom, tg_op, data, source_id, table_name) 
              SELECT OLD.the_geom, 'DELETE', row_to_json(OLD), OLD.cartodb_id, TG_TABLE_NAME::text;
            RETURN OLD;
        ELSIF (TG_OP = 'UPDATE') THEN
            INSERT INTO version_control(the_geom, tg_op, data, source_id, table_name) 
              SELECT NEW.the_geom, 'UPDATE', row_to_json(NEW), NEW.cartodb_id, TG_TABLE_NAME::text;
            RETURN NEW;
        END IF;
        RETURN NULL; 
    END;
$$ LANGUAGE plpgsql;

-- 
-- Add a trigger to any table that you want to store change history
-- The following adds the trigger, simply change the table name from
-- 'your_important_table' to the name of the table you want to track
--
CREATE TRIGGER axh_version_trigger
AFTER UPDATE OR DELETE ON your_important_table
    FOR EACH ROW EXECUTE PROCEDURE axh_version_control();


--
-- To extract a record from the version_control table you can filter
-- and then explode the JSON record like this
--
SELECT (json_populate_record(null::fake_data, data)).* FROM version_control LIMIT 1