**entities**
id
entity_type_id
....

**entity_type_attributes**
id
entity_type_id
valuable_type (AppSomeValuableModelInt)
valuable_id - should be dynamic
....

**entity_attribute_value_text**
id
entity_id
entity_type_attribute_id
value
....

**entity_attribute_value_int**
id
entity_id
entity_type_attribute_id
value
....

**entity_attribute_value_datetime**
id
entity_id
entity_type_attribute_id
value
....