clickhouse
analytics OLAP database.
Created:
Home page – Fast Open-Source OLAP DBMS - ClickHouse
clickhouse-local is an easy-to-use version of ClickHouse that is ideal for developers who need to perform fast processing on local and remote files using SQL without having to install a full database server. With
clickhouse-local
, developers can use SQL commands (using the ClickHouse SQL dialect) directly from the command line, providing a simple and efficient way to access ClickHouse features without the need for a full ClickHouse installation. One of the main benefits ofclickhouse-local
is that it is already included when installing clickhouse-client. This means that developers can get started withclickhouse-local
quickly, without the need for a complex installation process.
curl https://clickhouse.com/ | sh
will download a single
clickhouse
binary, which can be used as
clickhouse-local
:
./clickhouse local -q "SELECT * FROM file('reviews.tsv', 'TabSeparated')"
# to see the inferred schema
./clickhouse local -q "DESCRIBE file('reviews.tsv')"
# a query
./clickhouse local -q "SELECT
argMax(product_title,star_rating),
max(star_rating)
FROM file('reviews.tsv')"
This can also be used to query data in a parquet file on S3 storage:
./clickhouse local -q "
SELECT count()
FROM s3('https://datasets-documentation.s3.eu-west-3.amazonaws.com/house_parquet/house_0.parquet')"
chDB - embedded SQL OLAP Engine powered by ClickHouse
The birth of chDB - auxten – “rocket engine on a bicycle”. github.
- In-process SQL OLAP Engine, powered by ClickHouse
- No need to install ClickHouse
- Minimized data copy from C++ to Python with python memoryview
- Input&Output support Parquet, CSV, JSON, Arrow, ORC and 60+more formats, samples
- Support Python DB API 2.0, example
pip install chdb
= "SELECT distinct city from 'employees.csv' "
query = chdb.query(query, "CSV")
res print(res)
See Trying chDB, an embeddable ClickHouse engine for more code examples.
TODO: What’s the comparison to duckdb and where would one shine over the other?
Comparisons
ClickHouse or StarRocks? Here is a DETAILED Comparison | by Tianyi Wang | Dec, 2021 | Medium (archive).