diff --git a/src/UserGuide/Master/Table/Basic-Concept/Delete-Data.md b/src/UserGuide/Master/Table/Basic-Concept/Delete-Data.md index 9a3e0071a..86a9492e7 100644 --- a/src/UserGuide/Master/Table/Basic-Concept/Delete-Data.md +++ b/src/UserGuide/Master/Table/Basic-Concept/Delete-Data.md @@ -25,6 +25,11 @@ Data deletion in IoTDB can be achieved using the DELETE statement. You can specify filters based on tags and time to delete specific subsets of data. +Note: +When executing a conventional data deletion command (the DELETE FROM statement), disk space is not immediately released. Instead, the data is marked first, and disk space is gradually freed by background tasks. +You can speed up this process by adjusting the parameters `inner_compaction_task_selection_disk_redundancy` and `inner_compaction_task_selection_mods_file_threshold` to smaller values. +The database deletion command (the DROP DATABASE statement) can immediately release disk space. + ### 1.1 Syntax Overview ```SQL diff --git a/src/UserGuide/Master/Tree/Basic-Concept/Delete-Data.md b/src/UserGuide/Master/Tree/Basic-Concept/Delete-Data.md index 8c4d883c4..cda39aab3 100644 --- a/src/UserGuide/Master/Tree/Basic-Concept/Delete-Data.md +++ b/src/UserGuide/Master/Tree/Basic-Concept/Delete-Data.md @@ -24,6 +24,11 @@ Users can delete data that meet the deletion condition in the specified timeseri In a JAVA programming environment, you can use the Java JDBC to execute single or batch UPDATE statements. +Note: +When executing a conventional data deletion command (the DELETE FROM statement), disk space is not immediately released. Instead, the data is marked first, and disk space is gradually freed by background tasks. +You can speed up this process by adjusting the parameters `inner_compaction_task_selection_disk_redundancy` and `inner_compaction_task_selection_mods_file_threshold` to smaller values. +The database deletion command (the DROP DATABASE statement) can immediately release disk space. + ## 1. Delete Single Timeseries Taking ln Group as an example, there exists such a usage scenario: diff --git a/src/UserGuide/latest-Table/Basic-Concept/Delete-Data.md b/src/UserGuide/latest-Table/Basic-Concept/Delete-Data.md index 9a3e0071a..86a9492e7 100644 --- a/src/UserGuide/latest-Table/Basic-Concept/Delete-Data.md +++ b/src/UserGuide/latest-Table/Basic-Concept/Delete-Data.md @@ -25,6 +25,11 @@ Data deletion in IoTDB can be achieved using the DELETE statement. You can specify filters based on tags and time to delete specific subsets of data. +Note: +When executing a conventional data deletion command (the DELETE FROM statement), disk space is not immediately released. Instead, the data is marked first, and disk space is gradually freed by background tasks. +You can speed up this process by adjusting the parameters `inner_compaction_task_selection_disk_redundancy` and `inner_compaction_task_selection_mods_file_threshold` to smaller values. +The database deletion command (the DROP DATABASE statement) can immediately release disk space. + ### 1.1 Syntax Overview ```SQL diff --git a/src/UserGuide/latest/Basic-Concept/Delete-Data.md b/src/UserGuide/latest/Basic-Concept/Delete-Data.md index 8c4d883c4..cda39aab3 100644 --- a/src/UserGuide/latest/Basic-Concept/Delete-Data.md +++ b/src/UserGuide/latest/Basic-Concept/Delete-Data.md @@ -24,6 +24,11 @@ Users can delete data that meet the deletion condition in the specified timeseri In a JAVA programming environment, you can use the Java JDBC to execute single or batch UPDATE statements. +Note: +When executing a conventional data deletion command (the DELETE FROM statement), disk space is not immediately released. Instead, the data is marked first, and disk space is gradually freed by background tasks. +You can speed up this process by adjusting the parameters `inner_compaction_task_selection_disk_redundancy` and `inner_compaction_task_selection_mods_file_threshold` to smaller values. +The database deletion command (the DROP DATABASE statement) can immediately release disk space. + ## 1. Delete Single Timeseries Taking ln Group as an example, there exists such a usage scenario: diff --git a/src/zh/UserGuide/Master/Table/Basic-Concept/Delete-Data.md b/src/zh/UserGuide/Master/Table/Basic-Concept/Delete-Data.md index 136cf8087..9772b59a8 100644 --- a/src/zh/UserGuide/Master/Table/Basic-Concept/Delete-Data.md +++ b/src/zh/UserGuide/Master/Table/Basic-Concept/Delete-Data.md @@ -25,6 +25,11 @@ 数据删除可以通过 delete 语句来完成，其中可以通过指定标签和时间的过滤条件来删除部分数据。 +注意： +常规的数据删除命令 （DELETE FROM 语句）执行后不会立即释放磁盘空间，而是先对数据进行标记，依靠后台任务逐步地去释放空间。 +调小参数 `inner_compaction_task_selection_disk_redundancy` 和 `inner_compaction_task_selection_mods_file_threshold` 可以加快该过程。 +删除数据库命令（DROP DATABASE 语句）可以立即释放磁盘空间。 + ### 1.1 语法概览 ```SQL diff --git a/src/zh/UserGuide/Master/Tree/Basic-Concept/Delete-Data.md b/src/zh/UserGuide/Master/Tree/Basic-Concept/Delete-Data.md index 184429c5b..f36f76b1b 100644 --- a/src/zh/UserGuide/Master/Tree/Basic-Concept/Delete-Data.md +++ b/src/zh/UserGuide/Master/Tree/Basic-Concept/Delete-Data.md @@ -20,10 +20,15 @@ --> # 数据删除 -用户使用 [DELETE 语句](../SQL-Manual/SQL-Manual.md#删除数据) 可以删除指定的时间序列中符合时间删除条件的数据。在删除数据时，用户可以选择需要删除的一个或多个时间序列、时间序列的前缀、时间序列带、*路径对某一个时间区间内的数据进行删除。 +用户使用 DELETE 语句可以删除指定的时间序列中符合时间删除条件的数据。在删除数据时，用户可以选择需要删除的一个或多个时间序列、时间序列的前缀、时间序列带、*路径对某一个时间区间内的数据进行删除。 在 JAVA 编程环境中，您可以使用 JDBC API 单条或批量执行 DELETE 语句。 +注意： +常规的数据删除命令 （DELETE FROM 语句）执行后不会立即释放磁盘空间，而是先对数据进行标记，依靠后台任务逐步地去释放空间。 +调小参数 `inner_compaction_task_selection_disk_redundancy` 和 `inner_compaction_task_selection_mods_file_threshold` 可以加快该过程。 +删除数据库命令（DROP DATABASE 语句）可以立即释放磁盘空间。 + ## 1. 单传感器时间序列值删除 以测控 ln 集团为例，存在这样的使用场景： diff --git a/src/zh/UserGuide/latest-Table/Basic-Concept/Delete-Data.md b/src/zh/UserGuide/latest-Table/Basic-Concept/Delete-Data.md index 136cf8087..9772b59a8 100644 --- a/src/zh/UserGuide/latest-Table/Basic-Concept/Delete-Data.md +++ b/src/zh/UserGuide/latest-Table/Basic-Concept/Delete-Data.md @@ -25,6 +25,11 @@ 数据删除可以通过 delete 语句来完成，其中可以通过指定标签和时间的过滤条件来删除部分数据。 +注意： +常规的数据删除命令 （DELETE FROM 语句）执行后不会立即释放磁盘空间，而是先对数据进行标记，依靠后台任务逐步地去释放空间。 +调小参数 `inner_compaction_task_selection_disk_redundancy` 和 `inner_compaction_task_selection_mods_file_threshold` 可以加快该过程。 +删除数据库命令（DROP DATABASE 语句）可以立即释放磁盘空间。 + ### 1.1 语法概览 ```SQL diff --git a/src/zh/UserGuide/latest/Basic-Concept/Delete-Data.md b/src/zh/UserGuide/latest/Basic-Concept/Delete-Data.md index 184429c5b..f36f76b1b 100644 --- a/src/zh/UserGuide/latest/Basic-Concept/Delete-Data.md +++ b/src/zh/UserGuide/latest/Basic-Concept/Delete-Data.md @@ -20,10 +20,15 @@ --> # 数据删除 -用户使用 [DELETE 语句](../SQL-Manual/SQL-Manual.md#删除数据) 可以删除指定的时间序列中符合时间删除条件的数据。在删除数据时，用户可以选择需要删除的一个或多个时间序列、时间序列的前缀、时间序列带、*路径对某一个时间区间内的数据进行删除。 +用户使用 DELETE 语句可以删除指定的时间序列中符合时间删除条件的数据。在删除数据时，用户可以选择需要删除的一个或多个时间序列、时间序列的前缀、时间序列带、*路径对某一个时间区间内的数据进行删除。 在 JAVA 编程环境中，您可以使用 JDBC API 单条或批量执行 DELETE 语句。 +注意： +常规的数据删除命令 （DELETE FROM 语句）执行后不会立即释放磁盘空间，而是先对数据进行标记，依靠后台任务逐步地去释放空间。 +调小参数 `inner_compaction_task_selection_disk_redundancy` 和 `inner_compaction_task_selection_mods_file_threshold` 可以加快该过程。 +删除数据库命令（DROP DATABASE 语句）可以立即释放磁盘空间。 + ## 1. 单传感器时间序列值删除 以测控 ln 集团为例，存在这样的使用场景：