以sysdba身份登陆ORACLE进行管理，有2种验证方式: 操作系统验证及密码文件验证

windows下在sqlnet.ora文件中
authentication_services
=(NTS) 操作系统验证           
=(NONE) 口令验证 
=(NTS,NONE) 操作系统验证(因为操作系统认证比口令认证的安全级别高)

++++++++++++++++++++++++++++++++++++D:\oracle\ora92\network\admin
# SQLNET.ORA Network Configuration File: D:\oracle\ora92\network\admin\sqlnet.ora
# Generated by Oracle configuration tools.

NAMES.DEFAULT_DOMAIN = asia.ad.flextronics.com

SQLNET.AUTHENTICATION_SERVICES= (NTS)

NAMES.DIRECTORY_PATH= (TNSNAMES, ONAMES, HOSTNAME)
++++++++++++++++++++++++++++++++++++

linux/unix下 只要在sqlnet文件中出现 authentication_services就为密码验证,不管其值是NTS,NONE还是2者皆有.