From 98ce30f55cb4c52a2fa8fbf47123b15c4090e133 Mon Sep 17 00:00:00 2001 From: wangmm0220 Date: Wed, 28 Jun 2023 19:26:34 +0800 Subject: [PATCH] docs:modify docs for tmq --- docs/en/07-develop/07-tmq.mdx | 15 ++++++++++----- docs/en/12-taos-sql/24-show.md | 2 +- docs/zh/07-develop/07-tmq.mdx | 12 ++++++++---- docs/zh/12-taos-sql/24-show.md | 2 +- 4 files changed, 20 insertions(+), 11 deletions(-) diff --git a/docs/en/07-develop/07-tmq.mdx b/docs/en/07-develop/07-tmq.mdx index 578f38e73d..f5e0378a00 100644 --- a/docs/en/07-develop/07-tmq.mdx +++ b/docs/en/07-develop/07-tmq.mdx @@ -244,6 +244,8 @@ The following SQL statement creates a topic in TDengine: CREATE TOPIC topic_name AS SELECT ts, c1, c2, c3 FROM tmqdb.stb WHERE c1 > 1; ``` +- There is an upper limit to the number of topics created, controlled by the parameter tmqMaxTopicNum, with a default of 20 + Multiple subscription types are supported. #### Subscribe to a Column @@ -265,14 +267,15 @@ You can subscribe to a topic through a SELECT statement. Statements that specify Syntax: ```sql -CREATE TOPIC topic_name AS STABLE stb_name +CREATE TOPIC topic_name [with meta] AS STABLE stb_name [where_condition] ``` Creating a topic in this manner differs from a `SELECT * from stbName` statement as follows: - The table schema can be modified. - Unstructured data is returned. The format of the data returned changes based on the supertable schema. -- A different table schema may exist for every data block to be processed. +- The 'with meta' parameter is optional. When selected, statements such as creating super tables and sub tables will be returned, mainly used for Taosx to perform super table migration +- The 'where_condition' parameter is optional and will be used to filter and subscribe to sub tables that meet the criteria. Where conditions cannot have ordinary columns, only tags or tbnames. Functions can be used in where conditions to filter tags, but cannot be aggregate functions because sub table tag values cannot be aggregated. It can also be a constant expression, such as 2>1 (subscribing to all child tables), Or false (subscribe to 0 sub tables) - The data returned does not include tags. ### Subscribe to a Database @@ -280,10 +283,12 @@ Creating a topic in this manner differs from a `SELECT * from stbName` statement Syntax: ```sql -CREATE TOPIC topic_name [WITH META] AS DATABASE db_name; +CREATE TOPIC topic_name [with meta] AS DATABASE db_name; ``` -This SQL statement creates a subscription to all tables in the database. You can add the `WITH META` parameter to include schema changes in the subscription, including creating and deleting supertables; adding, deleting, and modifying columns; and creating, deleting, and modifying the tags of subtables. Consumers can determine the message type from the API. Note that this differs from Kafka. +This SQL statement creates a subscription to all tables in the database. + +- The 'with meta' parameter is optional. When selected, it will return statements for creating all super tables and sub tables in the database, mainly used for Taosx database migration ## Create a Consumer @@ -295,7 +300,7 @@ You configure the following parameters when creating a consumer: | `td.connect.user` | string | User Name | | | `td.connect.pass` | string | Password | | | `td.connect.port` | string | Port of the server side | | -| `group.id` | string | Consumer group ID; consumers with the same ID are in the same group | **Required**. Maximum length: 192. | +| `group.id` | string | Consumer group ID; consumers with the same ID are in the same group | **Required**. Maximum length: 192. Each topic can create up to 100 consumer groups. | | `client.id` | string | Client ID | Maximum length: 192. | | `auto.offset.reset` | enum | Initial offset for the consumer group | Specify `earliest`, `latest`, or `none`(default) | | `enable.auto.commit` | boolean | Commit automatically; true: user application doesn't need to explicitly commit; false: user application need to handle commit by itself | Default value is true | diff --git a/docs/en/12-taos-sql/24-show.md b/docs/en/12-taos-sql/24-show.md index eb70a7664b..bd4a60b20e 100644 --- a/docs/en/12-taos-sql/24-show.md +++ b/docs/en/12-taos-sql/24-show.md @@ -36,7 +36,7 @@ Shows information about connections to the system. SHOW CONSUMERS; ``` -Shows information about all active consumers in the system. +Shows information about all consumers in the system. ## SHOW CREATE DATABASE diff --git a/docs/zh/07-develop/07-tmq.mdx b/docs/zh/07-develop/07-tmq.mdx index a87a1f64f8..54a8af2287 100644 --- a/docs/zh/07-develop/07-tmq.mdx +++ b/docs/zh/07-develop/07-tmq.mdx @@ -243,6 +243,7 @@ TDengine 使用 SQL 创建一个 topic： ```sql CREATE TOPIC topic_name AS SELECT ts, c1, c2, c3 FROM tmqdb.stb WHERE c1 > 1; ``` +- topic创建个数有上限，通过参数 tmqMaxTopicNum 控制，默认 20 个 TMQ 支持多种订阅类型： @@ -265,14 +266,15 @@ CREATE TOPIC topic_name as subquery 语法： ```sql -CREATE TOPIC topic_name AS STABLE stb_name +CREATE TOPIC topic_name [with meta] AS STABLE stb_name [where_condition] ``` 与 `SELECT * from stbName` 订阅的区别是： - 不会限制用户的表结构变更。 - 返回的是非结构化的数据：返回数据的结构会随之超级表的表结构变化而变化。 -- 用户对于要处理的每一个数据块都可能有不同的表结构。 +- with meta 参数可选，选择时将返回创建超级表，子表等语句，主要用于taosx做超级表迁移 +- where_condition 参数可选，选择时将用来过滤符合条件的子表，订阅这些子表。where 条件里不能有普通列，只能是tag或tbname，where条件里可以用函数，用来过滤tag，但是不能是聚合函数，因为子表tag值无法做聚合。也可以是常量表达式，比如 2 > 1（订阅全部子表），或者 false（订阅0个子表） - 返回数据不包含标签。 ### 数据库订阅 @@ -280,11 +282,13 @@ CREATE TOPIC topic_name AS STABLE stb_name 语法： ```sql -CREATE TOPIC topic_name AS DATABASE db_name; +CREATE TOPIC topic_name [with meta] AS DATABASE db_name; ``` 通过该语句可创建一个包含数据库所有表数据的订阅 +- with meta 参数可选，选择时将返回创建数据库里所有超级表，子表的语句，主要用于taosx做数据库迁移 + ## 创建消费者 *consumer* 消费者需要通过一系列配置选项创建，基础配置项如下表所示： @@ -295,7 +299,7 @@ CREATE TOPIC topic_name AS DATABASE db_name; | `td.connect.user` | string | 用户名 | | | `td.connect.pass` | string | 密码 | | | `td.connect.port` | integer | 服务端的端口号 | | -| `group.id` | string | 消费组 ID，同一消费组共享消费进度 | **必填项**。最大长度：192。 | +| `group.id` | string | 消费组 ID，同一消费组共享消费进度 |
**必填项**。最大长度：192。
每个topic最多可建立100个 consumer group | | `client.id` | string | 客户端 ID | 最大长度：192。 | | `auto.offset.reset` | enum | 消费组订阅的初始位置 |
`earliest`: default;从头开始订阅;
`latest`: 仅从最新数据开始订阅;
`none`: 没有提交的 offset 无法订阅 | | `enable.auto.commit` | boolean | 是否启用消费位点自动提交，true: 自动提交，客户端应用无需commit；false：客户端应用需要自行commit | 默认值为 true | diff --git a/docs/zh/12-taos-sql/24-show.md b/docs/zh/12-taos-sql/24-show.md index 12ad665e42..f3397ae82d 100644 --- a/docs/zh/12-taos-sql/24-show.md +++ b/docs/zh/12-taos-sql/24-show.md @@ -36,7 +36,7 @@ SHOW CONNECTIONS; SHOW CONSUMERS; ``` -显示当前数据库下所有活跃的消费者的信息。 +显示当前数据库下所有消费者的信息。 ## SHOW CREATE DATABASE -- GitLab