ClickHouse's SQL dialect description:
- Query Language | ClickHouse Docs:
- supports most standard SQL features such as SELECT, FROM, WHERE, GROUP BY, ORDER BY, JOIN, and UNION.
- support for subqueries, materialized views, and window functions.
- Functions | ClickHouse Docs
- rich set of built-in functions
- Aggregate Functions | ClickHouse Docs
- rollups, cube sets, grouping sets, pivot and unpivot tables.
- support for user-defined functions (UDFs) in several programming languages such as C++, Python, and JavaScript.
- Syntax | ClickHouse Docs:
- similar to standard SQL
- uses backticks instead of double quotes to delimit identifiers
- uses square brackets instead of single quotes for string literals.
- Indexing (A Practical Introduction to Primary Indexes in ClickHouse | ClickHouse Docs):
- no traditional indexing methods like B-trees or hash indexes.
- Instead, it uses a unique indexing system called 'MergeTree'. It allows for efficient data retrieval by using sorted, compressed data blocks.