1. A computer-implemented method executed by one or more processors, the method comprising: identifying, by the one or more processors, a data processing function to be executed in a hybrid main memory system, the hybrid main memory system including a first type of main memory and a second type of main memory, the data processing function including data access operations to access the hybrid main memory system; accessing, by the one or more processors, a write metric for the data processing function, the write metric based at least in part on a proportion of the data access operations that are write operations; and based at least in part on the write metric being less than a threshold value, designating, by the one or more processors, the data processing function for execution in the first type of main memory.