INFORMATION_SCHEMA.TABLES
基础表信息,包含字段:TABLE_CATALOG, TABLE_SCHEMA, TABLE_NAME, TABLE_TYPE
sys.dm_exec_sessions
会话表
SELECT host_name,login_name,program_name,client_interface_name,max(login_time) t,count(1) c
from sys.dm_exec_sessions
group by host_name,login_name,program_name,client_interface_name