OpenRefine has some means of managing the memory allocation to make it possible for large datasets to be manipulated (see https://docs.openrefine.org/manual/installing#increasing-memory-allocation)
Where are the similar options in GraphDB's version? (OntoRefine is a customization of OpenRefine but I cannot find the initialization files for controlling memory allocation in OntoRefine).
This question pertains to GraphDB 9.11 and I don't know the answer.
Ontotext Refine 1.0 was split off in GraphDB 10, so you control it as a separate java server app. See this documentation: