mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-11-24 08:32:02 +00:00
ClickHouse® is a real-time analytics DBMS
18e8f0eb5e
This way the remote nodes will not need to send all the rows, so this
will decrease network io and also this will make queries w/
optimize_aggregation_in_order=1/LIMIT X and w/o ORDER BY faster since it
initiator will not need to read all the rows, only first X (but note
that for this you need to your data to be sharded correctly or you may
get inaccurate results).
Note, that having lots of processing stages will increase the complexity
of interpreter (it is already not that clean and simple right now).
Although using separate QueryProcessingStage looks pretty natural.
Another option is to make WithMergeableStateAfterAggregation always, but
in this case you will not be able to disable only this optimization,
i.e. if there will be some issue with it.
v2: fix OFFSET
v3: convert 01814_distributed_push_down_limit test to .sh and add retries
v4: add test with OFFSET
v5: add new query stage into the bash completion
v6/tests: use LIMIT O,L syntax over LIMIT L OFFSET O since it is broken in ANTLR parser
https://clickhouse-test-reports.s3.yandex.net/23027/a18a06399b7aeacba7c50b5d1e981ada5df19745/functional_stateless_tests_(antlr_debug).html#fail1
v7/tests: set use_hedged_requests to 0, to avoid excessive log entries on retries
https://clickhouse-test-reports.s3.yandex.net/23027/a18a06399b7aeacba7c50b5d1e981ada5df19745/functional_stateless_tests_flaky_check_(address).html#fail1
|
||
|---|---|---|
| .github | ||
| base | ||
| benchmark | ||
| cmake | ||
| contrib | ||
| debian | ||
| docker | ||
| docs | ||
| programs | ||
| src | ||
| tests | ||
| utils | ||
| website | ||
| .arcignore | ||
| .clang-format | ||
| .clang-tidy | ||
| .editorconfig | ||
| .gitattributes | ||
| .gitignore | ||
| .gitmodules | ||
| .potato.yml | ||
| .pylintrc | ||
| .vimrc | ||
| .yamllint | ||
| AUTHORS | ||
| CHANGELOG.md | ||
| CMakeLists.txt | ||
| CODE_OF_CONDUCT.md | ||
| CONTRIBUTING.md | ||
| docker-compose.yml | ||
| format_sources | ||
| LICENSE | ||
| PreLoad.cmake | ||
| README.md | ||
| release | ||
| SECURITY.md | ||
| uncrustify.cfg | ||
| ya.make | ||
ClickHouse® is an open-source column-oriented database management system that allows generating analytical data reports in real time.
Useful Links
- Official website has quick high-level overview of ClickHouse on main page.
- Tutorial shows how to set up and query small ClickHouse cluster.
- Documentation provides more in-depth information.
- YouTube channel has a lot of content about ClickHouse in video format.
- Slack and Telegram allow to chat with ClickHouse users in real-time.
- Blog contains various ClickHouse-related articles, as well as announcements and reports about events.
- Code Browser with syntax highlight and navigation.
- Contacts can help to get your questions answered if there are any.
- You can also fill this form to meet Yandex ClickHouse team in person.
Upcoming Events
- SF Bay Area ClickHouse Community Meetup (online) on 16 June 2021.