Wide-column stores
On This Lesson 4 topics
This lesson is planned. The outline below lists the topics it will cover. The full lesson has not been published yet.
In this lesson
understand tables designed for huge write volume and known queries.
Planned topics
- Cassandra, ScyllaDB, HBase: rows are found by a partition key, ordered inside the partition by clustering columns.
- A table is designed for one query; the same data is duplicated into several tables for several queries.
- Writes are very fast and scale out; queries without the partition key are not supported or are slow.
- Consistency is tunable per request; many designs favor availability (see CAP and PACELC).
Draft outline details
Demonstration
table reviews_by_product(product_id, created_at, review_id, rating) with partition key product_id and clustering created_at DESC: "latest reviews of a product" is one partition read.
Check your understanding
Why duplicate data in wide-column?
Show answer
Each query needs its own table with the right partition key.
Practice
Apply this lesson with the module's lab, exercises and quiz.
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