It would be nice if you can change a database without having to execute "postfix reload", in order to force Postfix to use the new information. Each time you do "postfix reload" Postfix loses a lot of performance.
[ ....]
If you change a local file based database such as DBM or Berkeley DB, there is no need to execute "postfix reload". Postfix uses file locking to avoid read/write access conflicts, and whenever a Postfix daemon process notices that a file has changed it will terminate before handling the next client request, so that a new process can initialize with the new database.
In dbfile.pp the line "notify => Service["postfix"]," is not necessary; in fact it may be undesirable.
Quote from http://www.postfix.org/DATABASE_README.html:
It would be nice if you can change a database without having to execute "postfix reload", in order to force Postfix to use the new information. Each time you do "postfix reload" Postfix loses a lot of performance.
[ ....]
If you change a local file based database such as DBM or Berkeley DB, there is no need to execute "postfix reload". Postfix uses file locking to avoid read/write access conflicts, and whenever a Postfix daemon process notices that a file has changed it will terminate before handling the next client request, so that a new process can initialize with the new database.