ClickHouse

https://clickhouse.com/

Fast Open-Source OLAP DBMS - ClickHouse

 

ClickHouse® is a column-oriented database management system (DBMS) for online analytical processing of queries (OLAP). ClickHouse’s performance exceeds all other column-oriented database management systems. It processes billions of rows and tens of gigabytes of data per server per second.

문서 지원언어가 러시아어와 중국어라 Apache Kylin 과 같이 찝찝함이 남아 있다.

Glance at ClickHouse Features
- Blazing fast
- SQL-based, feature-rich
- Linear scalability & reliability
- Open Source (Apache 2.0)
- No Hadoop ecosystem

The ClickHouse Architecture

ClickHouse was designed for OLAP workloads, which have specific characteristics. From the ClickHouse documentation, here are some of the requirements for this type of workload: 

• The vast majority of requests are for read access.
• Data is inserted in fairly large batches (> 1000 rows), not by single rows; or it is not updated at all.
• Data is added to the DB but is not modified.
• For reads, quite a large number of rows are processed from the DB, but only a small subset of columns.
• Tables are “wide,” meaning they contain a large number of columns.
• Queries are relatively rare (usually hundreds of queries per server or less per second).
• For simple queries, latencies around 50 ms are allowed.
• Column values are fairly small: numbers and short strings (for example, 60 bytes per URL).
• Requires high throughput when processing a single query (up to billions of rows per second per server).
• Transactions are not necessary.
• Low requirements for data consistency.
• There is one large table per query. All tables are small, except for one.
• A query result is significantly smaller than the source data. In other words, data is filtered or aggregated, so the result fits in a single server’s RAM.

 

Apache Druid vs ClickHouse

https://imply.io/druid-vs-clickhouse/

Druid vs ClickHouse - Imply