我收到以下错误：
ERROR: canceling statement due to conflict with recovery.
Detail: User query might have needed to see row versions that must be removed.;
nested exception in org.postgresql.util.PSQLException:ERROR:canceling statement due to conflict with recovery.
Detail: User query might have needed to see row versions that must be removed.
当我们使用长查询时，此错误发生在备用数据库上。我们使用 PostgreSQL 版本 12.0。一台主服务器和两台备用服务器。
您能给我们解决方案吗？