doc(stream): add new trigger type (#30276)
* doc(stream): add new trigger type * doc: adjust stream doc * doc: adjust doc
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@ -26,7 +26,7 @@ CREATE STREAM [IF NOT EXISTS] stream_name [stream_options] INTO stb_name
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SUBTABLE(expression) AS subquery
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stream_options: {
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TRIGGER [AT_ONCE | WINDOW_CLOSE | MAX_DELAY time | FORCE_WINDOW_CLOSE]
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TRIGGER [AT_ONCE | WINDOW_CLOSE | MAX_DELAY time | FORCE_WINDOW_CLOSE | CONTINUOUS_WINDOW_CLOSE [recalculate rec_time_val] ]
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WATERMARK time
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IGNORE EXPIRED [0|1]
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DELETE_MARK time
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@ -147,6 +147,7 @@ When creating a stream, you can specify the trigger mode of stream computing thr
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```sql
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create stream if not exists continuous_query_s trigger force_window_close into continuous_query as select count(*) from power.meters interval(10s) sliding(1s)
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```
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5. CONTINUOUS_WINDOW_CLOSE: Results are output when the window is closed. Modifying or deleting data does not immediately trigger a recalculation. Instead, periodic recalculations are performed every rec_time_val duration. If rec_time_val is not specified, the recalculation period is 60 minutes. If the recalculation time exceeds rec_time_val, the next recalculation will be automatically initiated after the current one is completed. Currently, this mode only supports INTERVAL windows. If the FILL clause is used, relevant information of the adapter needs to be configured, including adapterFqdn, adapterPort, and adapterToken. The adapterToken is a string obtained by Base64-encoding `{username}:{password}`. For example, after encoding `root:taosdata`, the result is `cm9vdDp0YW9zZGF0YQ==`.
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The closing of the window is determined by the event time, such as when the event stream is interrupted or continuously delayed, at which point the event time cannot be updated, possibly leading to outdated computation results.
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Therefore, stream computing provides the MAX_DELAY trigger mode that combines event time with processing time: MAX_DELAY mode triggers computation immediately when the window closes, and its unit can be specified, specific units: a (milliseconds), s (seconds), m (minutes), h (hours), d (days), w (weeks). Additionally, when data is written, if the time that triggers computation exceeds the time specified by MAX_DELAY, computation is triggered immediately.
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@ -246,6 +246,9 @@ The effective value of charset is UTF-8.
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| streamSinkDataRate | |Supported, effective after restart| Internal parameter, used to control the write speed of stream computing results |
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| streamNotifyMessageSize | After 3.3.6.0 | Not supported | Internal parameter, controls the message size for event notifications, default value is 8192 |
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| streamNotifyFrameSize | After 3.3.6.0 | Not supported | Internal parameter, controls the underlying frame size when sending event notification messages, default value is 256 |
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| adapterFqdn | After 3.3.6.0 | Not supported | Internal parameter, The address of the taosadapter services, default value is localhost |
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| adapterPort | After 3.3.6.0 | Not supported | Internal parameter, The port of the taosadapter services, default value is 6041 |
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| adapterToken | After 3.3.6.0 | Not supported | Internal parameter, The string obtained by Base64-encoding `{username}:{password}`, default value is `cm9vdDp0YW9zZGF0YQ==` |
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### Log Related
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@ -11,7 +11,7 @@ import imgStream from './assets/stream-processing-01.png';
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```sql
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CREATE STREAM [IF NOT EXISTS] stream_name [stream_options] INTO stb_name[(field1_name, field2_name [PRIMARY KEY], ...)] [TAGS (create_definition [, create_definition] ...)] SUBTABLE(expression) AS subquery [notification_definition]
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stream_options: {
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TRIGGER [AT_ONCE | WINDOW_CLOSE | MAX_DELAY time | FORCE_WINDOW_CLOSE]
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TRIGGER [AT_ONCE | WINDOW_CLOSE | MAX_DELAY time | FORCE_WINDOW_CLOSE | CONTINUOUS_WINDOW_CLOSE [recalculate rec_time_val] ]
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WATERMARK time
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IGNORE EXPIRED [0|1]
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DELETE_MARK time
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@ -164,6 +164,7 @@ For non-window computations, the trigger of stream computing is real-time; for w
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2. WINDOW_CLOSE: Triggered when the window closes (window closure is determined by event time, can be used in conjunction with watermark)
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3. MAX_DELAY time: Trigger computation if the window closes. If the window does not close, and the time since it has not closed exceeds the time specified by max delay, then trigger computation.
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4. FORCE_WINDOW_CLOSE: Based on the current time of the operating system, only compute and push the results of the currently closed window. The window is only computed once at the moment of closure and will not be recalculated subsequently. This mode currently only supports INTERVAL windows (does not support sliding); FILL_HISTORY must be 0, IGNORE EXPIRED must be 1, IGNORE UPDATE must be 1; FILL only supports PREV, NULL, NONE, VALUE.
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5. CONTINUOUS_WINDOW_CLOSE: Results are output when the window is closed. Modifying or deleting data does not immediately trigger a recalculation. Instead, periodic recalculations are performed every rec_time_val duration. If rec_time_val is not specified, the recalculation period is 60 minutes. If the recalculation time exceeds rec_time_val, the next recalculation will be automatically initiated after the current one is completed. Currently, this mode only supports INTERVAL windows. If the FILL clause is used, relevant information of the adapter needs to be configured, including adapterFqdn, adapterPort, and adapterToken. The adapterToken is a string obtained by Base64-encoding `{username}:{password}`. For example, after encoding `root:taosdata`, the result is `cm9vdDp0YW9zZGF0YQ==`.
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Since the closure of the window is determined by event time, if the event stream is interrupted or continuously delayed, the event time cannot be updated, which may result in not obtaining the latest computation results.
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@ -23,7 +23,7 @@ CREATE STREAM [IF NOT EXISTS] stream_name [stream_options] INTO stb_name
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SUBTABLE(expression) AS subquery
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stream_options: {
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TRIGGER [AT_ONCE | WINDOW_CLOSE | MAX_DELAY time | FORCE_WINDOW_CLOSE]
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TRIGGER [AT_ONCE | WINDOW_CLOSE | MAX_DELAY time | FORCE_WINDOW_CLOSE | CONTINUOUS_WINDOW_CLOSE [recalculate rec_time_val] ]
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WATERMARK time
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IGNORE EXPIRED [0|1]
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DELETE_MARK time
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@ -136,6 +136,7 @@ create stream if not exists count_history_s fill_history 1 into count_history as
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```sql
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create stream if not exists continuous_query_s trigger force_window_close into continuous_query as select count(*) from power.meters interval(10s) sliding(1s)
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```
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5. CONTINUOUS_WINDOW_CLOSE：窗口关闭时输出结果。修改、删除数据，并不会立即触发重算，每等待 rec_time_val 时长，会进行周期性重算。如果不指定 rec_time_val，那么重算周期是60分钟。如果重算的时间长度超过 rec_time_val，在本次重算后，自动开启下一次重算。该模式当前只支持 INTERVAL 窗口。如果使用 FILL，需要配置 adapter的相关信息：adapterFqdn、adapterPort、adapterToken。adapterToken 为 `{username}:{password}` 经过 Base64 编码之后的字符串，例如 `root:taosdata` 编码后为 `cm9vdDp0YW9zZGF0YQ==`。
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窗口关闭是由事件时间决定的，如事件流中断、或持续延迟，此时事件时间无法更新，可能导致无法得到最新的计算结果。
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@ -1095,6 +1095,29 @@ charset 的有效值是 UTF-8。
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- 动态修改：不支持
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- 支持版本：v3.3.6.0 引入
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#### adapterFqdn
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- 说明：taosadapter服务的地址 `内部参数`
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- 类型：fqdn
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- 默认值：localhost
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- 动态修改：不支持
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- 支持版本：v3.3.6.0 引入
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#### adapterPort
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- 说明：taosadapter服务的端口号 `内部参数`
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- 类型：整数
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- 默认值：6041
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- 最小值：1
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- 最大值：65056
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- 动态修改：不支持
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- 支持版本：v3.3.6.0 引入
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#### adapterToken
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- 说明：为 `{username}:{password}` 经过 Base64 编码之后的字符串 `内部参数`
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- 类型：字符串
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- 默认值：`cm9vdDp0YW9zZGF0YQ==`
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- 动态修改：不支持
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- 支持版本：v3.3.6.0 引入
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### 日志相关
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#### logDir
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@ -10,7 +10,7 @@ description: 流式计算的相关 SQL 的详细语法
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```sql
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CREATE STREAM [IF NOT EXISTS] stream_name [stream_options] INTO stb_name[(field1_name, field2_name [PRIMARY KEY], ...)] [TAGS (create_definition [, create_definition] ...)] SUBTABLE(expression) AS subquery [notification_definition]
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stream_options: {
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TRIGGER [AT_ONCE | WINDOW_CLOSE | MAX_DELAY time | FORCE_WINDOW_CLOSE]
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TRIGGER [AT_ONCE | WINDOW_CLOSE | MAX_DELAY time | FORCE_WINDOW_CLOSE| CONTINUOUS_WINDOW_CLOSE [recalculate rec_time_val] ]
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WATERMARK time
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IGNORE EXPIRED [0|1]
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DELETE_MARK time
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@ -165,8 +165,11 @@ SELECT * from information_schema.`ins_streams`;
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2. WINDOW_CLOSE：窗口关闭时触发（窗口关闭由事件时间决定，可配合 watermark 使用）
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3. MAX_DELAY time：若窗口关闭，则触发计算。若窗口未关闭，且未关闭时长超过 max delay 指定的时间，则触发计算。
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4. FORCE_WINDOW_CLOSE：以操作系统当前时间为准，只计算当前关闭窗口的结果，并推送出去。窗口只会在被关闭的时刻计算一次，后续不会再重复计算。该模式当前只支持 INTERVAL 窗口（不支持滑动）；FILL_HISTORY 必须为 0，IGNORE EXPIRED 必须为 1，IGNORE UPDATE 必须为 1；FILL 只支持 PREV、NULL、NONE、VALUE。
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5. CONTINUOUS_WINDOW_CLOSE：窗口关闭时输出结果。修改、删除数据，并不会立即触发重算，每等待 rec_time_val 时长，会进行周期性重算。如果不指定 rec_time_val，那么重算周期是60分钟。如果重算的时间长度超过 rec_time_val，在本次重算后，自动开启下一次重算。该模式当前只支持 INTERVAL 窗口。如果使用 FILL，需要配置 adapter的相关信息：adapterFqdn、adapterPort、adapterToken。adapterToken 为 `{username}:{password}` 经过 Base64 编码之后的字符串，例如 `root:taosdata` 编码后为 `cm9vdDp0YW9zZGF0YQ==`
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由于窗口关闭是由事件时间决定的，如事件流中断、或持续延迟，则事件时间无法更新，可能导致无法得到最新的计算结果。
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因此，流式计算提供了以事件时间结合处理时间计算的 MAX_DELAY 触发模式。MAX_DELAY 最小时间是 5s，如果低于 5s，创建流计算时会报错。
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