Decreased memory usage when the workload is heavy?

I have a specific job that should be run with a decreased memory usage when the workload is heavy on the SQL Server.

This is a heavy job that has no specific requirement when it comes to response time.

It is important that the rest of the application shouldn't be affected with longer response time when this job is running.

How can this job bee handled from the application, without having to create a separate batch job.

You cannot limit the amount of memory to be used for a certain process. If you are worried the production would be affected during peak hours, have a reporting server that you replicate to and run your process off of it.