I need to updated millions of records which is of currency type.So i need to write business logic for the same.So shall i go with trigger or Batch class. In the case of a trigger, every time an invoice record is added, deleted or modified Amount will be recalculated.While in case of batch class,records will be updated based on a process that can be scheduled to run on a specific day and time of the month.
We have recently released a new salesforce App called Rubrik which may help you with your updates. Rubrik is used to do mass update/creation/deletion of records based on user defined criteria. We know making mass changes can be scary, so there is the ability to preview the changes before fully committing them to the database. There is also a functionality to use Rubrik as a trigger, to process records as they are inserted/updated. This allows Administrators to do tasks that would usually require a developer.
In your case, you could use Rubrik to update your million of records one time and then set up Rubrik as a trigger to process any new records after.
You can learn more here: Rubrik Features
To try out Rubrik, please go to here: Free Trial