ClickHouse/docs/zh/engines/table-engines/log-family/stripelog.md
BayoNet 4ec7821fec
DOCS-624: Fixing links to nowhere 2 (#10703)
* enbaskakova-DOCSUP-652 (#101)

* "docs(orNull&orDefault): Functions 'orNull&orDefault' have been edited"

* "docs(orNull&orDefault): Functions 'orNull&orDefault' have been edited"

* "docs(orNull&orDefault): Functions 'orNull&orDefault' have been edited"

* Update docs/en/sql_reference/aggregate_functions/combinators.md

Co-Authored-By: BayoNet <da-daos@yandex.ru>

* Update docs/en/sql_reference/aggregate_functions/combinators.md

Co-Authored-By: BayoNet <da-daos@yandex.ru>

* Update docs/en/sql_reference/aggregate_functions/combinators.md

Co-Authored-By: BayoNet <da-daos@yandex.ru>

* Update docs/en/sql_reference/aggregate_functions/combinators.md

Co-Authored-By: BayoNet <da-daos@yandex.ru>

* Update docs/en/sql_reference/aggregate_functions/combinators.md

Co-Authored-By: BayoNet <da-daos@yandex.ru>

* "docs(orNull&orDefault): Functions 'orNull&orDefault' have been edited"

* "docs(orNull&orDefault): Functions 'orNull&orDefault' have been edited"

* "docs(orNull&orDefault): Functions 'orNull&orDefault' have been edited"

Co-authored-by: elenbaskakova <elenbaskakova@yandex-team.ru>
Co-authored-by: BayoNet <da-daos@yandex.ru>

* Revert "enbaskakova-DOCSUP-652 (#101)" (#107)

This reverts commit 639fee7610.

* CLICKHOUSEDOCS-624: Fixed en

* CLICKHOUSEDOCS-624: Fixed RU.

* CLICKHOUSEDOCS-624: Fixed ES and FR.

* CLICKHOUSEDOCS-624: Fixed JA and TR

* CLICKHOUSEDOCS-624: Fixed FA.

* CLICKHOUSEDOCS-624: Fixed ZH.

* Update docs/tools/test.py

Co-authored-by: Ivan Blinkov <github@blinkov.ru>

* Update docs/tools/test.py

Co-authored-by: Ivan Blinkov <github@blinkov.ru>

Co-authored-by: elenaspb2019 <47083263+elenaspb2019@users.noreply.github.com>
Co-authored-by: elenbaskakova <elenbaskakova@yandex-team.ru>
Co-authored-by: Sergei Shtykov <bayonet@yandex-team.ru>
Co-authored-by: Ivan Blinkov <github@blinkov.ru>
2020-05-06 22:28:06 +03:00

83 lines
3.9 KiB
Markdown
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

# StripeLog {#stripelog}
该引擎属于日志引擎系列。请在[日志引擎系列](log-family.md)文章中查看引擎的共同属性和差异。
在你需要写入许多小数据量(小于一百万行)的表的场景下使用这个引擎。
## 建表 {#table_engines-stripelog-creating-a-table}
CREATE TABLE [IF NOT EXISTS] [db.]table_name [ON CLUSTER cluster]
(
column1_name [type1] [DEFAULT|MATERIALIZED|ALIAS expr1],
column2_name [type2] [DEFAULT|MATERIALIZED|ALIAS expr2],
...
) ENGINE = StripeLog
查看[建表](../../../engines/table-engines/log-family/stripelog.md#create-table-query)请求的详细说明。
## 写数据 {#table_engines-stripelog-writing-the-data}
`StripeLog` 引擎将所有列存储在一个文件中。对每一次 `Insert` 请求ClickHouse 将数据块追加在表文件的末尾,逐列写入。
ClickHouse 为每张表写入以下文件:
- `data.bin` — 数据文件。
- `index.mrk` — 带标记的文件。标记包含了已插入的每个数据块中每列的偏移量。
`StripeLog` 引擎不支持 `ALTER UPDATE``ALTER DELETE` 操作。
## 读数据 {#table_engines-stripelog-reading-the-data}
带标记的文件使得 ClickHouse 可以并行的读取数据。这意味着 `SELECT` 请求返回行的顺序是不可预测的。使用 `ORDER BY` 子句对行进行排序。
## 使用示例 {#table_engines-stripelog-example-of-use}
建表:
``` sql
CREATE TABLE stripe_log_table
(
timestamp DateTime,
message_type String,
message String
)
ENGINE = StripeLog
```
插入数据:
``` sql
INSERT INTO stripe_log_table VALUES (now(),'REGULAR','The first regular message')
INSERT INTO stripe_log_table VALUES (now(),'REGULAR','The second regular message'),(now(),'WARNING','The first warning message')
```
我们使用两次 `INSERT` 请求从而在 `data.bin` 文件中创建两个数据块。
ClickHouse 在查询数据时使用多线程。每个线程读取单独的数据块并在完成后独立的返回结果行。这样的结果是,大多数情况下,输出中块的顺序和输入时相应块的顺序是不同的。例如:
``` sql
SELECT * FROM stripe_log_table
```
┌───────────timestamp─┬─message_type─┬─message────────────────────┐
│ 2019-01-18 14:27:32 │ REGULAR │ The second regular message │
│ 2019-01-18 14:34:53 │ WARNING │ The first warning message │
└─────────────────────┴──────────────┴────────────────────────────┘
┌───────────timestamp─┬─message_type─┬─message───────────────────┐
│ 2019-01-18 14:23:43 │ REGULAR │ The first regular message │
└─────────────────────┴──────────────┴───────────────────────────┘
对结果排序(默认增序):
``` sql
SELECT * FROM stripe_log_table ORDER BY timestamp
```
┌───────────timestamp─┬─message_type─┬─message────────────────────┐
│ 2019-01-18 14:23:43 │ REGULAR │ The first regular message │
│ 2019-01-18 14:27:32 │ REGULAR │ The second regular message │
│ 2019-01-18 14:34:53 │ WARNING │ The first warning message │
└─────────────────────┴──────────────┴────────────────────────────┘
[来源文章](https://clickhouse.tech/docs/en/operations/table_engines/stripelog/) <!--hide-->