使用客户端工具连接pg，连接失败，报错以下错误：
FATAL: remaining connection slots are reserved for non-replication superuser connections
查看数据库连接状态和配置信息
select * from pg_stat_activity where pid<>pg_backend_pid() and state=‘idle‘;##pg_backend_pid()的结果是当前会话的pid select datname,datconnlimit from pg_database ; select current_setting(‘max_connections‘); select current_setting(‘superuser_reserved_connections‘);
发现参数max_connections设置太低。
因为是测试环境，就先把idle状态的连接先杀掉：
##把数据库中的所有的空闲会话全部kill掉 select pg_terminate_backend(pid) from pg_stat_activity where pid<>pg_backend_pid() and state=‘idle‘;
然后修改参数max_connections的值。
remaining connection slots are reserved for non-replication superuser connections
原文：https://www.cnblogs.com/abclife/p/10955132.html