NYSDOT found an intermittent performance bug with our Roads and Highways Enterprise Geodatabse (10.5.1). The issue manifested itself when attempting to use snapping in an edit session. Rather than snap to the appropriate feature, ArcGIS would present a loading icon and never really "snapped".
We were able to track this down to a database issue, and the R&H team helped submit a bug report to the ArcGIS geodatabase team. There's been some movement on the issue, so we wanted to share it with the RHUG community. Here's the system generated email:
The status of Esri BUG-000118270 - Extreme latency in snapping until a feature cache is created. - that you have been associated with has been changed to Not in Current Product Plan.
Public Explanation: Spatial queries without a spatial index are full table scans, and will be significantly slower than those that utilize an index.
The case of snapping across the WAN has an existing solution, the feature cache, which was built to support users that required snapping in all of their editing workflows.
See An Overview of spatial indexes in the geodatabase: http://desktop.arcgis.com/en/arcmap/latest/manage-data/geodatabases/an-overview-of-spatial-indexes-i...
Case Number: 02229254
Our particular issue falls under the second point in the "Public Explanation".
The R&H team had suggested the Feature Cache toolbar as a workaround while we were submitting this issue. After playing with it for about a month, I've started to use it consistently in my editing workflow. As long as your map scale is set to a reasonable level, the feature cache toolbar builds a cache in <= 30 seconds. The map then becomes extremely responsive as you conduct the edit.
Hopefully this helps some of you.
