Due to the sequential search in the aggregates model_contents.instances and actual entity_extent.instances, a delete instance operation may be very slow when the actual model has a large number of instances. Hence for large models with a large number of delete instance (model merge) operation should use the EDMpersistentInstancesHashTable to speed up such delete instance operations. The EDMpersistenInstancesHashTable must be specified when the actual model is created. Hence, the functionality to specify this concept is available in all create model operations. The actual option is named
PERSISTENT_INSTANCES_HASH_TABLE.
The functions edmiHashModelInstances and xpxHashModelInstances will fail on models that already have an EDMpersistentInstancesHashTable.