1. A computer program product comprising a machine-readable medium storing instructions that, when executed by at least one programmable processor, cause the at least one programmable processor to perform operations comprising: assigning each of a plurality of database objects in a database management system to a specific message-passing worker of a plurality of message-passing workers, each of the plurality of message-passing workers executing on a first logical core that shares with at least a second logical core one or more resources of a physical processor core of a plurality of physical processor cores, the second logical core executing a job worker of a plurality of job workers that implement procedural code; providing exclusive write access to a database object of the plurality of database objects via a message-passing worker of the plurality of message-passing workers to which the database object is assigned; providing read-only access to any database object of the plurality of database objects via any of the plurality of job workers; and executing operations by the message-passing worker in an order in which request messages are received in a message queue of the message-passing worker.