sql – HBase中的高级查询

发布时间：2020-12-12 06:41:28 所属栏目：MsSql教程来源：网络整理

导读：鉴于以下HBase架构场景( from the official FAQ)…… How would you design an Hbase table for many-to-many association between two entities,for example Student and Course? I would define two tables: Student: student id student data (name,addres

鉴于以下HBase架构场景( from the official FAQ)……

How would you design an Hbase table
for many-to-many association between
two entities,for example Student and
Course?

I would define two tables:

Student: student id student data
(name,address,…) courses (use
course ids as column qualifiers here)

Course: course id course data (name,
syllabus,…) students (use student
ids as column qualifiers here)

This schema gives you fast access to
the queries,show all classes for a
student (student table,courses
family),or all students for a class
(courses table,students family).

您如何满足这一要求：“给我所有共享至少两门共同课程的学生”？您可以在HBase中构建一个返回该集合的“查询”,还是必须检索所有相关数据并在代码中自行处理？

解决方法

所描述的查询更适合于关系数据库.但是,您可以通过预先计算结果来快速回答查询.例如,您可能有一个表,其中键是共同的类的数量,并且单元格是具有共同键的许多类的单个学生.

你可以使用一个变体来回答诸如“哪个学生在X班和Y班”中这样的问题：将这些类用作键的部分(按字母顺序排列,或者至少是一致的),同样,每列都是一个学生.

（编辑：李大同）

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