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Re:MySQL和PostgreSQL的优劣 [Re:tanzhi]

sho

发贴: 99
积分: 88

于 2003-03-02 16:23

我認為應該加上價格上的比較....
postgresql是100% free......
但mysql在很多情形下不是free......
價格可看http://www.mysql.com/products/pricing.html
以下轉自http://www.mysql.com/products/licensing.html
In Brief

This is our licensing policy in brief: Our software is 100% GPL, and if yours is
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
also 100% GPL (or OSI compliant), then you never have to pay us for the
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
licences. In all other instances, you are better served by our commercial
~~~~~
licence. Read the details below!
Licensing

MySQL software is licensed under the GPL license. The formal terms of the GPL license can be found in the GNU General Public License section of the MySQL Reference Manual.

MySQL is also available under commercial non-GPL license. For pricing and ordering information, see our online store
1. Free use for those who are 100% GPL

If your application is licensed under GPL or compatible OSI license approved by MySQL AB, you are free and welcome to ship any GPL software of MySQL AB with your application. By "application" we mean any type of software application, system, tool or utility. For doing this, you do not need a separate signed agreement with MySQL AB, because the GPL text is sufficient. But we do recommend you to be in touch with us as there usually are good opportunities for partnership and co-marketing.
2. Free use for those who never copy, modify or distribute

As long as you never distribute (internally or externally) the MySQL Software in any way, you are free to use it for powering your application, irrespective of whether your application is under GPL or other OSI approved license or not.

More specifically:

Modifying - You are allowed to modify MySQL Software source code any way you like. If you distribute the modified version, all changes, all interface code and all code that connects directly or indirectly to the interface code fall under GPL.

Copying - You are allowed to copy MySQL binaries and source code, but when you do so, the copies will fall under the GPL license.
3. Commercial use for everyone else

If your application is not licensed under GPL or compatible OSI license approved by MySQL AB and you intend to distribute MySQL software (be that internally or externally), you must first obtain a commercial license to the MySQL software in question.

More specifically:

a) If you include the MySQL server in your non Open Source application, you need a commercial licence for the MySQL server

b) If you include one of the MySQL drivers in your non Open Source application (so that your application can run with MySQL), you need a commercial licence for the driver(s) in question. The MySQL drivers currently include an ODBC driver, a JDBC driver and the C language library.

c) If you use MySQL Software within your organisation and you don't want to risk it falling under the GPL license, you are welcome to purchase a commercial license.

d) Many users opt for the commercial licence simply because under it MySQL AB takes responsibility for its products. Under the GPL licence, there are no warranties or representations from the developer (i.e. from MySQL AB).
4. Exceptions and free commercial licences

If you represent a non-profit organisation or an academic institution, we recommend you to put your own application under GPL. Thereby you are free to use MySQL software free of charge under the GPL licence. (We also believe that if you have strong reasons not to go GPL, you also have the monetary means to purchase commercial licences.)

If you are a private individual you are free to use MySQL software for your personal applications, as long as you do not distribute them.

Please note that even if you ship a free demo version of your own application, the above rules apply.
5. Finally, what is the recommendation?

To all commercial organisations we do recommend the commercial licence. Not only does this free you from the far-reaching requirements of the GPL licence, it also gives you a licence letter from MySQL AB where we assume responsibility for our product. The GPL licence is an "as is" licence with no warranties whatsoever.

To all GPL/Open Source enthusiasts we do recommend our products under the GPL licence. We believe that MySQL AB is the world's largest company that offers all its software under the GPL licence. So help yourself to the MySQL server and the drivers and feel the freedom of free software!

To anyone in doubt, we recommend the commercial licence. It is never wrong. Thanks to our cost-effective way of producing software, we are able to sell our commercial licences at prices well under the industry average, and this is without compromising our own profitability. And, as evidenced by benchmarks and our installed base of millions, our software beats the old legacy databases in both performance and stability.
Older Versions

Note that older versions of the MySQL database server are still using a stricter license. See the documentation for the specific version for more information.
MySQL Licenses

For circumstances under which a commercial non-GPL MySQL server license is required, you need a license per database server (single installed MySQL binary). There are no restrictions on the number of connections, number of CPUs, memory or disks to that one database server.

For circumstances under which a commercial non-GPL MySQL client license is required, you need a license per each installed application.
When in doubt

If you have any questions on MySQL licensing, feel free to contact us.

OSI = Open Source Initiative, www.opensource.org/licenses
GPL = Gnu General Public License, http://www.gnu.org/copyleft/gpl.html

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话题树型展开

人气	标题	作者	字数	发贴时间
6786	[精华] MySQL和PostgreSQL的优劣	tanzhi	3051	2003-03-02 15:04
5636	Re:MySQL和PostgreSQL的优劣	sho	5752	2003-03-02 16:23
5862	Re:MySQL和PostgreSQL的优劣	chaos	87	2003-03-02 17:46
5752	Re:MySQL和PostgreSQL的优劣	jenson	43	2003-03-02 18:54

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