Oracle – Parameter:license_max_users
今天看书的时候了解到了与License相关的这个参数:“license_max_users”。
与之相关的参数还包括:
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SQL> show parameter license NAME TYPE VALUE ------------------------------------ ----------- ------------------------------ license_max_sessions integer 0 license_max_users integer 37 license_sessions_warning integer 0 SQL> |
license_max_users,可以限定能够在数据库中创建的最大用户数。
要查看当前数据库的已有用户数可以如下操作:
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SQL> select count(*) from dba_users; COUNT(*) ---------- 36 SQL> |
license_max_users的设置不应该比这个值低,否则会报错:
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SQL> alter system set license_max_users=3 scope=both; alter system set license_max_users=3 scope=both * ERROR at line 1: ORA-02097: parameter cannot be modified because specified value is invalid ORA-00035: LICENSE_MAX_USERS cannot be less than current number of users SQL> |
如果达到了license_max_users的限定边界,那么,继续创建用户,将会反馈错误:
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SQL> select count(*) from dba_users; COUNT(*) ---------- 36 SQL> alter system set license_max_users=37 scope=both; System altered. SQL> show parameter license NAME TYPE VALUE ------------------------------------ ----------- ------------------------------ license_max_sessions integer 0 license_max_users integer 37 license_sessions_warning integer 0 SQL> SQL> create user adamhuan identified by oracle; User created. SQL> select count(*) from dba_users; COUNT(*) ---------- 37 SQL> SQL> create user angel_allah identified by oracle; create user angel_allah identified by oracle * ERROR at line 1: ORA-01985: cannot create user as LICENSE_MAX_USERS parameter exceeded SQL> |
当“license_max_users”为0的时候,表示不做限制。
关于“license_max_users”,Oracle官方给出了说明:
http://docs.oracle.com/database/121/REFRN/GUID-C185BB02-0BB1-4403-8A40-1990958BDF6E.htm#REFRN10080
从官方的说明里可以看到,官方并不建议设置该参数:
Note:
Oracle no longer offers licensing by the number of concurrent sessions. Therefore the LICENSE_MAX_SESSIONS and LICENSE_SESSIONS_WARNING initialization parameters have been deprecated.
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Done。