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For example: you could run one database statement per job and let these jobs run simultaneously; or you could run a maximum of e.g. 10 simultaneous processes of a standard job that handles any database statement or executable file. In the second case an order is assigned to the job that contains the sql statement or filename in its payload (see answer: Job Chains Concepts for jobs, job chains and orders).
Jobs can be configured to start with priorities by <job priority="..."/>. Use of priorities is operating system dependent, see priorities. Operating system priorities have no effect on database driven jobs that spend their lifetime in the database (server).
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