The problem of validating a given graph database instance against a given PG-Schema graph type without integrity constraints is NP- complete in terms of combined complexity and in PTIME in terms of data complexity. The combined complexity drops to PTIME when the alternation between type combinations and unions is suitably restricted

翻译：在无完整性约束条件下，给定图数据库实例对给定PG-Schema图类型的验证问题，其联合复杂度为NP完全，数据复杂度为多项式时间。当类型组合与并集的交替受到适当限制时，联合复杂度降至多项式时间。