Techniques are disclosed to manage use of a global pool of memory comprising at least a portion of the runtime-managed heap. A request to reserve use of a portion of the global pool of memory is received from each of a plurality of transactions comprising a transactional workload of a database management system. A corresponding portion of the global pool of memory is allocated to each of at least a subset of the requesting transactions, to be used as a local pool of memory available to be used by the transaction to process the transaction.