今天在论坛上看到有人讨论如果使用SQL Server作为SEPM的后台数据库，需要多少个CAL的问题：
 
If I do have to use SQL Server what type of licensing is required in terms of user CALs.  Is it a one-to-one relationship where each client that checks into a SEP 11 management server needs a SQL Server CAL?  Or do only the management agents on the SEPM server need a CAL since client machines technically check-in via HTTP and not directly to the database?
 
参与讨论的人持两种观点：
第一种认为SEP客户端不支持访问数据库，所以不需要许可，只有直接访问数据库的Manager才需要许可：
 
The SEP clients do not acess the DB directly. You'll just need to license the SQL DB for the SEPM, since the client talks to the SEPM, and then the SEPM talks to the Database.
 
另一种说法认为只要是使用了SQL服务的用户，都要购买CAL，因为客户端需要SQL的服务，需要为每个客户端购买CAL：
 
Microsoft are very clear on SQL Licensing:
  
A SQL Server CAL is required for a user or device to access or use the services or functionality of either edition of SQL Server.  
  
This statement effectively means that if you purchase user or device CAL's you MUST purchase enough CAL's to cover all your users or clients, NOT just for SEPM's.  I will leave you to do the math, but once you hit a certain number, processor licensing is MUCH cheaper!
 
呵呵，有意思的讨论，售前的工作参与得少，咋一看我也没了主意，于是到MS的官方网站查查吧：
 
SQL Server的许可分为三种：基于处理器的，基于用户的，基于客户端设备的。
 
用户或设备数量较大时或者说SQL服务器的负载较重时，使用processer许可比较划算。反正就使用user或device许可，如果user share device，就用device的，如果一个user多个device，就用user的。
 
关于间接使用SQL服务的客户端是否需要CAL的问题，MS的说法是：
 
In most cases, Microsoft requires a CAL for every device that accesses or uses the services of SQL Server 2005. If you are unsure whether a CAL is required, you should contact your Microsoft sales representative or account manager. Inquires can be directed to the Microsoft Sales and Partner Information line by calling (800) 426-9400.
 
有意思，In most cases是什么意思呢？不清楚就联系销售？呵呵，看来还有的商量。
 
按照我的经验，如果SQL作为前端Web服务器的后端，则Web服务器的用户需要购买许可，但是对于绝大多数Web服务器来说，用户是不固定的，所以这种情况都应该购买processor许可，我想其它使用SQL作为后台数据库的应用也应该是一样的。