mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-11-25 17:12:03 +00:00
DOCS-605: Description for the always_fetch_merged_part setting (#11921)
* Revolg DOCSUP-998 Document the always_fetch_merged_part setting (#123) * Add always_fetch_merged_part setting * revolg-DOCSUP-998-add_always_fetch_merged_part_setting link fixed * Apply suggestions from code review Co-authored-by: BayoNet <da-daos@yandex.ru> * Add always_fetch_merged_part setting. Updates. * Update docs/en/operations/settings/settings.md Co-authored-by: BayoNet <da-daos@yandex.ru> * Add always_fetch_merged_part setting. Updates. Co-authored-by: Olga Revyakina <revolg@yandex-team.ru> Co-authored-by: BayoNet <da-daos@yandex.ru> * CLICKHOUSEDOCS-605: Minor fixes. * CLICKHOUSEDOCS-605: Added Plausible to Adopters. * Update docs/ru/operations/settings/settings.md Co-authored-by: alesapin <alesapin@gmail.com> * Update docs/en/operations/settings/settings.md Co-authored-by: alesapin <alesapin@gmail.com> * CLICKHOUSEDOCS-605: Fixed access rights description. Co-authored-by: olgarev <56617294+olgarev@users.noreply.github.com> Co-authored-by: Olga Revyakina <revolg@yandex-team.ru> Co-authored-by: Sergei Shtykov <bayonet@yandex-team.ru> Co-authored-by: alesapin <alesapin@gmail.com>
This commit is contained in:
BayoNet
GitHub
parent
cc2cadb7f5
commit
e79be9b1ed
@ -50,7 +50,8 @@ toc_title: Adopters
|
||||
| <a href="http://www.pragma-innovation.fr/" class="favicon">Pragma Innovation</a> | Telemetry and Big Data Analysis | Main product | — | — | [Slides in English, October 2018](https://github.com/ClickHouse/clickhouse-presentations/blob/master/meetup18/4_pragma_innovation.pdf) |
|
||||
| <a href="https://www.qingcloud.com/" class="favicon">QINGCLOUD</a> | Cloud services | Main product | — | — | [Slides in Chinese, October 2018](https://github.com/ClickHouse/clickhouse-presentations/blob/master/meetup19/4.%20Cloud%20%2B%20TSDB%20for%20ClickHouse%20张健%20QingCloud.pdf) |
|
||||
| <a href="https://qrator.net" class="favicon">Qrator</a> | DDoS protection | Main product | — | — | [Blog Post, March 2019](https://blog.qrator.net/en/clickhouse-ddos-mitigation_37/) |
|
||||
| <a href="https://www.percent.cn/" class="favicon">Percent 百分点</a> | Analytics | Main Product | — | — | [Slides in Chinese, June 2019](https://github.com/ClickHouse/clickhouse-presentations/blob/master/meetup24/4.%20ClickHouse万亿数据双中心的设计与实践%20.pdf) |
|
||||
| <a href="https://www.percent.cn/" class="favicon">Percent 百分点</a> | Analytics | Main Product | — | — | [Slides in Chinese, June 2019](https://github.com/ClickHouse/clickhouse-presentations/blob/master/meetup24/4.%20ClickHouse万亿数据双中心的设计与实践%20.pdf) |
|
||||
| <a href="https://plausible.io/" class="favicon">Plausible</a> | Analytics | Main Product | — | — | [Blog post, June 2020](https://twitter.com/PlausibleHQ/status/1273889629087969280) |
|
||||
| <a href="https://rambler.ru" class="favicon">Rambler</a> | Internet services | Analytics | — | — | [Talk in Russian, April 2018](https://medium.com/@ramblertop/разработка-api-clickhouse-для-рамблер-топ-100-f4c7e56f3141) |
|
||||
| <a href="https://www.tencent.com" class="favicon">Tencent</a> | Messaging | Logging | — | — | [Talk in Chinese, November 2019](https://youtu.be/T-iVQRuw-QY?t=5050) |
|
||||
| <a href="https://trafficstars.com/" class="favicon">Traffic Stars</a> | AD network | — | — | — | [Slides in Russian, May 2018](https://github.com/ClickHouse/clickhouse-presentations/blob/master/meetup15/lightning/ninja.pdf) |
|
||||
|
||||
@ -34,7 +34,7 @@ By default, the ClickHouse server provides the `default` user account which is n
|
||||
If you just started using ClickHouse, consider the following scenario:
|
||||
|
||||
1. [Enable](#enabling-access-control) SQL-driven access control and account management for the `default` user.
|
||||
2. Log in to the `default` user account and create all the required users. Don’t forget to create an administrator account (`GRANT ALL ON *.* WITH GRANT OPTION TO admin_user_account`).
|
||||
2. Log in to the `default` user account and create all the required users. Don’t forget to create an administrator account (`GRANT ALL ON *.* TO admin_user_account WITH GRANT OPTION`).
|
||||
3. [Restrict permissions](../operations/settings/permissions-for-queries.md#permissions_for_queries) for the `default` user and disable SQL-driven access control and account management for it.
|
||||
|
||||
### Properties of Current Solution {#access-control-properties}
|
||||
|
||||
@ -1416,6 +1416,23 @@ Possible values:
|
||||
|
||||
Default value: 16.
|
||||
|
||||
## always_fetch_merged_part {#always_fetch_merged_part}
|
||||
|
||||
Prohibits data parts merging in [Replicated*MergeTree](../../engines/table-engines/mergetree-family/replication.md)-engine tables.
|
||||
|
||||
When merging is prohibited, the replica never merges parts and always downloads merged parts from other replicas. If there is no required data yet, the replica waits for it. CPU and disk load on the replica server decreases, but the network load on cluster increases. This setting can be useful on servers with relatively weak CPUs or slow disks, such as servers for backups storage.
|
||||
|
||||
Possible values:
|
||||
|
||||
- 0 — `Replicated*MergeTree`-engine tables merge data parts at the replica.
|
||||
- 1 — `Replicated*MergeTree`-engine tables don't merge data parts at the replica. The tables download merged data parts from other replicas.
|
||||
|
||||
Default value: 0.
|
||||
|
||||
**See Also**
|
||||
|
||||
- [Data Replication](../../engines/table-engines/mergetree-family/replication.md)
|
||||
|
||||
## background\_distributed\_schedule\_pool\_size {#background_distributed_schedule_pool_size}
|
||||
|
||||
Sets the number of threads performing background tasks for [distributed](../../engines/table-engines/special/distributed.md) sends. This setting is applied at ClickHouse server start and can’t be changed in a user session.
|
||||
|
||||
@ -31,7 +31,7 @@ ClickHouse поддерживает управление доступом на
|
||||
Если вы начали пользоваться ClickHouse недавно, попробуйте следующий сценарий:
|
||||
|
||||
1. [Включите](#enabling-access-control) SQL-ориентированное управление доступом для пользователя `default`.
|
||||
2. Войдите под пользователем `default` и создайте всех необходимых пользователей. Не забудьте создать аккаунт администратора (`GRANT ALL ON *.* WITH GRANT OPTION TO admin_user_account`).
|
||||
2. Войдите под пользователем `default` и создайте всех необходимых пользователей. Не забудьте создать аккаунт администратора (`GRANT ALL ON *.* TO admin_user_account WITH GRANT OPTION`).
|
||||
3. [Ограничьте разрешения](settings/permissions-for-queries.md#permissions_for_queries) для пользователя `default` и отключите для него SQL-ориентированное управление доступом.
|
||||
|
||||
### Особенности реализации {#access-control-properties}
|
||||
|
||||
@ -1205,6 +1205,23 @@ Default value: 0.
|
||||
|
||||
Значение по умолчанию: 16.
|
||||
|
||||
## always_fetch_merged_part {#always_fetch_merged_part}
|
||||
|
||||
Запрещает слияние данных для таблиц семейства [Replicated*MergeTree](../../engines/table-engines/mergetree-family/replication.md).
|
||||
|
||||
Если слияние запрещено, реплика никогда не выполняет слияние отдельных кусков данных, а всегда загружает объединённые данные из других реплик. Если объединённых данных пока нет, реплика ждет их появления. Нагрузка на процессор и диски на реплике уменьшается, но нагрузка на сеть в кластере возрастает. Настройка может быть полезна на репликах с относительно слабыми процессорами или медленными дисками, например, на репликах для хранения архивных данных.
|
||||
|
||||
Возможные значения:
|
||||
|
||||
- 0 — таблицы семейства `Replicated*MergeTree` выполняют слияние данных на реплике.
|
||||
- 1 — таблицы семейства `Replicated*MergeTree` не выполняют слияние данных на реплике, а загружают объединённые данные из других реплик.
|
||||
|
||||
Значение по умолчанию: 0.
|
||||
|
||||
**См. также:**
|
||||
|
||||
- [Репликация данных](../../engines/table-engines/mergetree-family/replication.md)
|
||||
|
||||
## transform_null_in {#transform_null_in}
|
||||
|
||||
Разрешает сравнивать значения [NULL](../../sql-reference/syntax.md#null-literal) в операторе [IN](../../sql-reference/operators/in.md).
|
||||
|
||||
Loading…
Reference in New Issue
Block a user