ClickHouse is developed by a Russian company called Yandex. It is designed for multiple projects within Yandex. Yandex needed a fast DBMS for analyzing large amount of data, which cannot be solved by its original solutions. So it began to develop its own column-oriented DBMS, which can handle analytical data on the internet scale. The prototype of ClickHouse appeared in 2009 and it was released in 2016 and then blazing fast.
ClickHouses provides two types of parsers: a full SQL parser and a data format parser. It uses SQL parser for all types of queries and the data format parser only for INSERT queries. Beyond the query language, it provides multiple user interfaces, including HTTP interface, JDBC driver, TCP interface, command-line client, etc.
Virtual Views Materialized Views
ClickHouse supports both virtual views and materialized views. The materialized views store data transformed by corresponding SELECT query. The SELECT query can contain DISTINCT, GROUP BY, ORDER BY, LIMIT, etc.
Decomposition Storage Model (Columnar)
ClickHouse is a column-oriented DBMS and it stores data by columns.
ClickHouse has multiple types of table engines. The type of the table engine determines where the data is stored, concurrent level, whether indexes are supported and some other properties. The table engines that store data on disks include TinyLog and Log. The Memory engine stores data in memory and this table engine is mainly used for temporary tables with external query data. The data of Memory engine will disapper after the server is restarted.