Nov 27, 2017
In this tutorial, our guest blogger Yegor Andreenko (@f1yegor) is talking about The ClickHouse Primary keys.
- How many columns could primary key have? And what is a layout of data on storage drive? Are there any theoretical/practical limits?
- Could columns with missing data at some rows be part of the primary key?
Jul 10, 2017
The guest article from ClickHouse evangelist Yegor Andreenko (@f1yegor) about an interesting extension of aggregate functions aggregate states, that can be used to pre-aggregate data that usually has to be kept in raw, like uniques.