Function IsPreDefinedPredicate

x/keys.go:861–865

IsPreDefinedPredicate returns true only if the predicate has been defined by dgraph internally in the initial schema. These are not allowed to be dropped, as well as any schema update which is different than the initial internal schema is also not allowed for these. For example, `dgraph.type` or ACL

(pred string)

//
// Pre-defined predicates are subset of reserved predicates.
func IsPreDefinedPredicate(pred string) bool {
	pred = ParseAttr(pred)
	_, ok := starAllPredicateMap[strings.ToLower(pred)]
	return ok || IsAclPredicate(pred) || IsOtherReservedPredicate(pred)
}

// IsAclPredicate returns true if the predicate is in the list of reserved
// predicates for the ACL feature.