ORA-01925:maximum of 80 enabled roles exceeded
max_enabled_roles 9i的参数，10g及以后都不用了。
指定用户session的最大enabled roles数。
MAX_ENABLED_ROLES specifies the maximum number of database roles that users can enable, including roles contained within other roles. The actual number of roles that users can enable is 2 plus the value of MAX_ENABLED_ROLES,
because each user has two additional roles, PUBLIC and the user‘s own role.
For example, if MAX_ENABLED_ROLES is set to 5, then user HR can have seven roles enabled (the five enabled by MAX_ENABLED_ROLES, plus PUBLIC and HR).
查查系统用得比较多role的用户，但这样查出来，还不包括以role授予给role再授予用户的嵌套情况
select grantee,count(*) from dba_role_privs group by grantee order by count(*) desc;
也可以直接查当前会话enable的role数量
select count(*) from session_roles;
如果用户登陆不上了，必然是授予太多role了。
可以改大参数，但要重启库。
alter system set max_enabled_roles=148 scope=spfile;
ORA-01925:maximum of 80 enabled roles exceeded,布布扣,bubuko.com
ORA-01925:maximum of 80 enabled roles exceeded
原文：http://blog.csdn.net/whiteoldbig/article/details/24870671
