在什么情况下，你在DynamoDB使用简单哈希键？ [英] In what situation do you use Simple Hash Keys on DynamoDB?

问题描述

简单哈希键似乎太简单写了一篇文章，而关于组合散/量程按键多写，因为组合散/量程按键是许多复杂的情况下很有用。但我相信，在常见的应用，许多表的设计应与简单的哈希键。在什么情况下你用简单的哈希键？

Simple Hash Keys seem to be too simple to write an article, while many write about Composite Hash/Range Keys, because Composite Hash/Range Keys are useful for many complex situations. But I believe that in common applications, many of tables should be designed with Simple Hash Keys. In what situation do you use Simple Hash Keys?

例如，当你设计层次模型像下面，你怎么设计为每个表的主键？ （所有的表比其他租户都tenant_id作为一个字段。）

For example, when you design hierarchical models like following, how do you design primary keys for each table? (All tables other than Tenant have tenant_id as a field.)

• 租户
• 用户
• 团队
• 项目
• 工作
• 团队成员

只有团队成员是由组合散/ RANGE键设计。其他人则用简单的哈希键设计。

Only "Team Member" is designed by Composite Hash/Range Key. Others are designed by Simple Hash Key.

• 租户是通过简单的哈希键设计。
• 用户，团队和项目的主键是复合（tenant_id，sub_id）。
• 任务的主键是复合（{tenant_id} _ {project_range_key}，sub_id）。
• 在团队成员的主键是复合（{tenant_id} _ {team_range_key}，{tenant_id} _ {user_range_key}）。

其中sub_id可以是一个序列号，created_at，否则

where sub_id can be a sequential number, created_at, or else.

在我张贴了这个问题，我更多地了解了DynamoDB和它的历史，我承认我的关注太多说不清楚了。

After I posted this question, I learned more about DynamoDB and its history, and I recognize my concern much clearly now.

在GSI由亚马逊发布了，我们必须以对tenant_id查询设计表格，如理念2。但是，现在我们可以使用GSI，所以我们可以设计表（例如团队，项目或任务）中的简单的哈希键和GSI的组合。是对的吗？？

Before GSI was released by Amazon, we had to design tables like "Idea 2" in order to query against "tenant_id". But now we can use GSI, so we can design tables (e.g. Team, Project or Task) using the combination of "Simple Hash Key and GSI". Is that right??

推荐答案

您使用单一哈希键表来描述一个项目。对于好例子，一个用户有很多信息，如姓名，年龄等，您可以创建一个用户表USER_ID为hashkey并作为属性的所有其他信息。

You use single hash key table to describe an item. For examle, a user have many info like name, age, etc. You can create a user table with user_id as hashkey and all other info as attributes.

您使用哈希范围架构来形容的关系。例如，一个组可以有多个用户。所以，你可以创建一个团队的成员的关系表与团队-ID为hashkey和用户ID的范围键。

You use hash-range schema to describe a relationship. For example, one team can have multiple users. So you can create a Team-Member-Relationship table with team-id as hashkey and user-id as range key.

在换句话说，绘制顶点是（用户，团队，项目）和边缘是它们之间的关系（1对1，1对多，多到许多等）的关系图。然后使用Hashkey架构边缘的顶点和Hash-范围模式。

In other words, draw a relationship diagram with vertex being (user, team, project) and edge being their relationship (1-to-1, 1-to-many, many-to-many, etc). Then use Hashkey schema for vertex and Hash-Range schema for edge.

谢谢！

厄尔本

这篇关于在什么情况下，你在DynamoDB使用简单哈希键？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！