Let's say you have some feature classes and tables that are registered with a GDB but are not not registered as versioned. You create spatial and column indexes on them within the DBMS (Not ArcCatalog). Will ESRI clients like ArcMap, ArcGIS Pro, ArcGIS Server, etc recognize and honor those indexes? In other words, is ArcCatalog required to create indexes for ESRI clients? If you don't use ArcCatalog will performance suffer?