The first thing you must do to prioritize your transactions is to enable priority queues on the server. You do this by enabling <priorities> (a child element of <systemsettings>) in the database configuration file. For example:

<systemsettings> 
  <priorities enabled=”true”/>
</systemsettings>

You must set this property when you initialize the database root directory. You cannot change the queueing behavior after the database starts.