Why do Attribute Rules only work in FGDB?

[ThomasColson]

The following only works in a FGDB, not an enterprise SQLArchive-enabled Feature class, non-versioned. Sum($feature.ONE + $feature.TWO + $feature.THREE) properly sums the values of those 3 fields in the CALC field. Works in FGDB though. Is there a known limitation to Attribute rules in SQL 2014?