The ArcGIS Pro manual (see https://pro.arcgis.com/en/pro-app/2.9/help/data/geodatabases/manage-oracle/configure-oracle-extproc.htm) says :

But even if st_shapelib and extproc are not configured at all, the ArcGIS Server services create extproc processes on the database server. How is this to be explained ...
... and why do they grow so rapidly during operation. In our customer’s environment ArcGIS Server produces extproc processes of exorbitant size which finally crash the database server:

Any idea (helping to understand) would be great!
@George_Thompson ?
Regards,
Martin