History of PL/SQL code changes

One can build a history of PL/SQL code changes by setting up an AFTER CREATE schema (or database) level trigger (available from Oracle 8.1.7). This way one can easily revert to previous code should someone make any catastrophic changes. Look at this example:

-- Create a table
CREATE TABLE SOURCE_HIST
AS SELECT SYSDATE CHANGE_DATE, USER_SOURCE.*
FROM USER_SOURCE WHERE 1=2;

-----create a trigger to store in that table

CREATE OR REPLACE TRIGGER change_hist
AFTER CREATE ON SCHEMA
DECLARE
BEGIN
IF ora_dict_obj_type IN
('PROCEDURE', 'FUNCTION', 'PACKAGE', 'PACKAGE BODY', 'TYPE')
THEN
INSERT INTO source_hist
SELECT SYSDATE, user_source.*
FROM user_source
WHERE TYPE = ora_dict_obj_type AND NAME = ora_dict_obj_name;
END IF;
EXCEPTION
WHEN OTHERS
THEN
raise_application_error (-20000, SQLERRM);
END;


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