Schema Limits

Number of Schema Elements

Datomic enforces the total number of schema elements to be fewer than 220, which includes schema attributes and value types. Attempts to create more than 220 schema elements will fail.

Namespace Restrictions

The :db namespace, and all :db.* namespaces, are reserved for use by Datomic.

Schema Element Restrictions

With the exception of :db/doc and :db/ident, names in the :db namespace and all :db.* namespaces are reserved for use in Datomic schema. Domain entities cannot use these names.