RDBMS不是***的解决方案，虽然有方法来适应用户定义的字段（见XML数据类型，EAV设计模式，或只是有备用的通用列），有时一个无模式数据库是一个不错的选择。

Yes, sometimes RDBMS are not the best solution, although there are ways to accomodate user defined fields (see XML Datatype, EAV design pattern, or just have spare generic columns) sometimes a schema free database is a good choice.

但是，在选择使用文档数据库之前，您需要确定您的要求，因为您会失去许多可能用于关系型模型

However, you need to nail down your requirements before choosing to go with a document database, as you will loose a lot of the power you may be used to with the relational model

例如...

如果您的RDBMS数据库中有多个表，研究MongoDB的功能为您提供满足这些需求。

If you would otherwise have multiple tables in your RDBMS database, you will need to research the features MongoDB affords you to accomodate these needs.

如果您需要以特定方式查询数据，那么您还需要研究MongoDB为您提供的服务。

If you will need to query the data in specific ways, again you need to research what MongoDB offers you.

我不会想到NoSQL是RDBMS的替代品，而是一个稍微不同的工具，带来了自己的优点和缺点，使它更适合一些项目。

I wouldnt think of NoSQL as replacement for RDBMS, rather a slightly different tool that brings its own sets of advantages and disadvantages making it more suitable for some projects than others.

（在某些情况下可能会使用这两个数据库，如果你决定沿着可能使用MongoDB的路线，一旦你研究了网站，具体问题，您可以访问Freenode IRC #mongodb频道）

(Both databases may be used in some circumstances. Also if you decide to go down the route of possibly using MongoDB, once you have researched the websites out there and have more specific questions, you can visit Freenode IRC #mongodb channel)