Overhead of Triggers VS Materialized View Logs

Question

If I need to log INSERTs, UPDTEs, and DELETEs on a table - is there a difference in the overhead of doing so via triggers vs MV logs?
Thanks

Answer 1

You said that MV log is marginally more efficient than a trigger. I am curious why. In what way do they work differently under the hood?If the essence of discussion is only why MV log is more efficient than trigger than I think Justin has pointed out below good technical points i.e.
1.You don't have to pass control over to the PL/SQL engine.
2.You're also writing the binary data that you'd put in the redo logs rather than column level data.
And below text from docs :
Internal Trigger for the Materialized View Log
When changes are made to the master table or master materialized view using DML, an internal trigger records information about the affected rows in the materialized view log. This information includes the values of the primary key, rowid, or object id, or both, as well as the values of the other columns logged in the materialized view log. This is an internal AFTER ROW trigger that is automatically activated when you create a materialized view log for the target master table or master materialized view. It inserts a row into the materialized view log whenever an INSERT, UPDATE, or DELETE statement modifies the table's data. This trigger is always the last trigger to fire.http://docs.oracle.com/cd/B28359_01/server.111/b28326/repmview.htm#i30732
3.Trigger i.e. we are coding to track the changes, MV log i.e. tool/technology which is provided by Oracle itself; so definately "We are not that much capable to write the code which is equal or more efficient than Oracle itself right ?"
In fact, functionality of MV is Instead of Trigger, but under the cover, with near to Oracle's internals.
Regards
Girish Sharma