We have been at ArcSDE 10.3.1/Oracle 12c for almost 2 years and have a lot of spatial views. Recently we found a few spatial views in existing ArcMap files do not match ArcCatalog (verified in both ArcGIS Desktop 10.3.1 and 10.5.1) in feature count, and we have to drag the spatial views from ArcCatalog into ArcMap to validate the count. Anybody knows why? This behavior really looks like a bug to me.
Is the underlying data versioned?
One is registered as archived, the other one is not, and both cases we only look at the Default version.
Is the one that is archived have more records than the other one?
Is the view "removing" out the non-valid records in the archived feature class?
What is the feature count difference?
All records are valid. The count difference between ArcMap and ArcCatalog is small, usually 1 - 3 missing in ArcMap. When a spatial view is dragged into ArcMap, it asks for selecting an unique field, which is usually objectid, then it calculates the initial extent and add the data to the map. Seems to me the missing ones are the new features that fall outside the initial extent.
What happens if you drop the view and re-create it? Do the # of records match then?
Not sure about the rational behind recreating the views. I am testing this in ArcSDE 10.5.1 where spatial views are registered with SDE. Got a feeling this issue would not occur in 10.5.1. ESRI made a big mistake when dropping SDE view support in 10.2 and 10.3, and glad it came back in 10.5.1.
If you recreate the view it may pick up the records that you say are outside the initial extent.
Not recreate the view, but redrag the view into ArcMap to recalculate the extent. Better to specify a larger extent than using the default calculation.