Juan Céspedes 

(or, how to use History Tables in PostgreSQL)

If you would like to store somewhere the full history of all the insertions, updates and deletions in all your tables (to maintain a wiki-like database), there is no simple way to do it... but here you can find a way to do it, in an article written by Thomas Liske.

It works in PostgreSQL, creating a PL/Perl database trigger called log_history() which adds a line to a new table called history.<SCHEMA>_<TABLENAME> with a timestamp (hist_ts), the operation (hist_op) and all the columns, whenever a INSERT, UPDATE or DELETE is executed. This effectively stores all the history of the tables where the trigger is used.

Here you can view the log_history trigger, and a simple function to bind the trigger on all the tables in a schema, history_create_triggers. You can call this function for schema "public" with SELECT history_create_triggers('public');

These two functions are written in PL/Perl and PL/pgSQL, respectively, so you have to add those language to your PostgreSQL database, if you have not already done so, with CREATE LANGUAGE plperl; and CREATE LANGUAGE plpgsql;