这里是DataStax公司给出的关于Data modeling example的参考:https://docs.datastax.com/en/cql/3.1/cql/ddl/ddl_intro_c.html 这是一篇描述数据模型实践的博文:http://www.infoq.com/cn/articles/best-practice-of-cassandra-data-model-design 关于Dynamic columns / wide rows?:https://www.datastax.com/dev...
The following figure shows an example of a Cassandra column family. Column A column is the basic data structure of Cassandra with three values, namely key or column name, value, and a time stamp. Given below is the structure of a column. ...
1. Text: This data type is used to store variable-length character strings. It is commonly used for storing textual data suchas names, descriptions, or any other type of free-form text. Example: "Hello, World!" 2. Integer: This data type is used to store whole numbers. It can represe...
Apache Cassandra is an open-source, NoSQL database designed to store data for applications that require fast read and write performance. For example, you can use Cassandra to store user profile information for online video games, device metadata for internet of things (IoT) applications, or ...
As an example, consider the state when W=1 (for the ONE consistency level) and R=N (for the ALL consistency level). In this scenario, the system is considered to be strongly consistent. Similarly, if W=N and R=1, then the system is strongly consistent. If we consider a QUORUM ...
Data Cells: 向Cassandra查询的时候,返回的就是collections of cells. 举个例子,假设我们创建下表: 在这个数据模型中,month和day是我们的composite partition key。 clustering keys是station_id和time.也就是说在这个model中,对于每一个Parition,cells的数量等于以下2个集合的数量和: ...
例如,下面的“ExampleTable”是一个 Cassandra 数据库表,其中包含名为“pk_int”的整数主键列、文本列命名值、列表列、映射列和名为“StringSet”的集列。 展开表 pk_intValue列出映射StringSet 1 “示例值 1” ["1", "2", "3"] {"S1": "a", "S2": "b"} {"A", "B", "C"} 3 “示例值...
email: sd@example.com, comment: be nice Joe Blow this isnt youtube commentTime: 1250557004 }, }, // 另一篇博客的评论 12222343 : { … } Comments CF属于super类型。这里key的设置我们可以非常方便的找到一篇Blog对应的所有评论信息。 配置信息 ...
After we’ve assigned our data types, we analyze our model by performing size calculations and testing out how the model works. We may make some adjustments based on our findings. Once again we’ll cover the data modeling process in more detail by working through our example. Before we get...
To show some examples of a good thought process, I will walk you through the design of a data model for some simple problems. Example 1: User Lookup The high-level requirement is "we have users and want to look them up". Let's go through the steps: Step 1: Determine what specific ...