Apache Cassandra Learning Step by Step (四): Data Modeling
日期：2014-05-17 浏览次数：21082 次
22 Feb 2012, by Bright Zheng (IT进行时)
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写在这章前面的几点牢骚或感慨：
1. 我发现建模是比较别扭的一件事情，尤其是你的脑子里都是RDBMS的ERD的时候；
2. 本人试图通过两者的建模过程体现思考要点，但感觉在NoSQL的建模上有点“那个”——如果不在大型项目上吃亏过或者直接受教于前辈，总感觉缺那么点味道；
3. 这篇是我写的最郁闷的一篇，而且可能后面需要无数个补丁，但管不了了，有错误才有感悟
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5.?Data Modeling
Data Modeling is one of the most important things in experiencing Cassandra, especially to those who have lots of experiences with RDBMS data modeling.
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By admiring Twissandra project, we name it as Jtwissandra as an example. If possible, I’ll try to create and implement it and share it in GitHub.
This is a simple example to showcase the NoSQL concepts by admiring the Twitter via Cassandra.
5.1.??Tranditional RDBMS Data Modeling
Following are the core Entities & Relationships if we’re modeling in RDBMS concepts.
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Here are some pseudo codes for demonstrating the business logic/requirements:
1. Adding a new user:
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USER.insert(user_id, user_name, user_password, create_timestamp); |
2. Following a friend:
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FRIEND.insert(user_id, followed_id, create_timestamp) ??????? as ($current_user_id, user_id, create_timestamp); FOLLOWER.insert(user_id, follower_id, create_timestamp) ??????? as (user_id, $current_user_id, create_timestamp); |
3. Tweetting:
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FRIEND.insert(user_id, followed_id, create_timestamp) ???? ???as ($current_user_id, user_id, create_timestamp); FOLLOWER.insert(user_id, follower_id, create_timestamp) ??????? as (user_id, $current_user_id, create_timestamp); |
