From 2af33b6e6e80ba1e965a36e0c515a140b728af00 Mon Sep 17 00:00:00 2001 From: Leto_b Date: Thu, 24 Jul 2025 11:05:55 +0800 Subject: [PATCH] ttl is based on the timestamp of data point not the write time --- src/UserGuide/Master/Table/Basic-Concept/TTL-Delete-Data.md | 1 + .../Master/Tree/Basic-Concept/Operate-Metadata_apache.md | 2 +- .../Master/Tree/Basic-Concept/Operate-Metadata_timecho.md | 2 +- src/UserGuide/Master/Tree/Basic-Concept/TTL-Delete.md | 2 +- src/UserGuide/V1.3.x/Basic-Concept/Operate-Metadata_apache.md | 2 +- src/UserGuide/V1.3.x/Basic-Concept/Operate-Metadata_timecho.md | 2 +- src/UserGuide/V1.3.x/Basic-Concept/TTL-Delete.md | 2 +- src/UserGuide/dev-1.3/Basic-Concept/Operate-Metadata_apache.md | 2 +- src/UserGuide/dev-1.3/Basic-Concept/Operate-Metadata_timecho.md | 2 +- src/UserGuide/dev-1.3/Basic-Concept/TTL-Delete.md | 2 +- src/UserGuide/latest-Table/Basic-Concept/TTL-Delete-Data.md | 1 + src/UserGuide/latest/Basic-Concept/Operate-Metadata_apache.md | 2 +- src/UserGuide/latest/Basic-Concept/Operate-Metadata_timecho.md | 2 +- src/UserGuide/latest/Basic-Concept/TTL-Delete.md | 2 +- src/zh/UserGuide/Master/Table/Basic-Concept/TTL-Delete-Data.md | 1 + .../Master/Tree/Basic-Concept/Operate-Metadata_apache.md | 2 +- .../Master/Tree/Basic-Concept/Operate-Metadata_timecho.md | 2 +- src/zh/UserGuide/Master/Tree/Basic-Concept/TTL-Delete.md | 2 +- .../UserGuide/V1.3.x/Basic-Concept/Operate-Metadata_apache.md | 2 +- .../UserGuide/V1.3.x/Basic-Concept/Operate-Metadata_timecho.md | 2 +- src/zh/UserGuide/V1.3.x/Basic-Concept/TTL-Delete.md | 2 +- .../UserGuide/dev-1.3/Basic-Concept/Operate-Metadata_apache.md | 2 +- .../UserGuide/dev-1.3/Basic-Concept/Operate-Metadata_timecho.md | 2 +- src/zh/UserGuide/dev-1.3/Basic-Concept/TTL-Delete.md | 2 +- src/zh/UserGuide/latest-Table/Basic-Concept/TTL-Delete-Data.md | 1 + .../UserGuide/latest/Basic-Concept/Operate-Metadata_apache.md | 2 +- .../UserGuide/latest/Basic-Concept/Operate-Metadata_timecho.md | 2 +- src/zh/UserGuide/latest/Basic-Concept/TTL-Delete.md | 2 +- 28 files changed, 28 insertions(+), 24 deletions(-) diff --git a/src/UserGuide/Master/Table/Basic-Concept/TTL-Delete-Data.md b/src/UserGuide/Master/Table/Basic-Concept/TTL-Delete-Data.md index be7619140..7cc533f63 100644 --- a/src/UserGuide/Master/Table/Basic-Concept/TTL-Delete-Data.md +++ b/src/UserGuide/Master/Table/Basic-Concept/TTL-Delete-Data.md @@ -32,6 +32,7 @@ TTL values are specified in milliseconds, and once data exceeds its defined life 1. TTL defines the expiration time of data in milliseconds, independent of the time precision configuration file. 2. Modifying TTL settings can cause temporary variations in data accessibility. 3. The system eventually removes expired data, though this process may involve some delay.。 +4. The TTL expiration check is based on the data point timestamp, not the write time. ## 2. Set TTL diff --git a/src/UserGuide/Master/Tree/Basic-Concept/Operate-Metadata_apache.md b/src/UserGuide/Master/Tree/Basic-Concept/Operate-Metadata_apache.md index 27d1e83d7..45beb7be2 100644 --- a/src/UserGuide/Master/Tree/Basic-Concept/Operate-Metadata_apache.md +++ b/src/UserGuide/Master/Tree/Basic-Concept/Operate-Metadata_apache.md @@ -248,7 +248,7 @@ IoTDB supports device-level TTL settings, which means it is able to delete old d The default unit of TTL is milliseconds. If the time precision in the configuration file changes to another, the TTL is still set to milliseconds. -When setting TTL, the system will look for all devices included in the set path and set TTL for these devices. The system will delete expired data at the device granularity. +When setting TTL, the system will look for all devices included in the set path and set TTL for these devices. The system will delete expired data at the device granularity. The expiration check here is based on the data point timestamp, not the write time. After the device data expires, it will not be queryable. The data in the disk file cannot be guaranteed to be deleted immediately, but it can be guaranteed to be deleted eventually. However, due to operational costs, the expired data will not be physically deleted right after expiring. The physical deletion is delayed until compaction. Therefore, before the data is physically deleted, if the TTL is reduced or lifted, it may cause data that was previously invisible due to TTL to reappear. diff --git a/src/UserGuide/Master/Tree/Basic-Concept/Operate-Metadata_timecho.md b/src/UserGuide/Master/Tree/Basic-Concept/Operate-Metadata_timecho.md index c73fe07bd..f60bf49ac 100644 --- a/src/UserGuide/Master/Tree/Basic-Concept/Operate-Metadata_timecho.md +++ b/src/UserGuide/Master/Tree/Basic-Concept/Operate-Metadata_timecho.md @@ -248,7 +248,7 @@ IoTDB supports device-level TTL settings, which means it is able to delete old d The default unit of TTL is milliseconds. If the time precision in the configuration file changes to another, the TTL is still set to milliseconds. -When setting TTL, the system will look for all devices included in the set path and set TTL for these devices. The system will delete expired data at the device granularity. +When setting TTL, the system will look for all devices included in the set path and set TTL for these devices. The system will delete expired data at the device granularity. The expiration check here is based on the data point timestamp, not the write time. After the device data expires, it will not be queryable. The data in the disk file cannot be guaranteed to be deleted immediately, but it can be guaranteed to be deleted eventually. However, due to operational costs, the expired data will not be physically deleted right after expiring. The physical deletion is delayed until compaction. Therefore, before the data is physically deleted, if the TTL is reduced or lifted, it may cause data that was previously invisible due to TTL to reappear. diff --git a/src/UserGuide/Master/Tree/Basic-Concept/TTL-Delete.md b/src/UserGuide/Master/Tree/Basic-Concept/TTL-Delete.md index 14b479fe2..97aa8380f 100644 --- a/src/UserGuide/Master/Tree/Basic-Concept/TTL-Delete.md +++ b/src/UserGuide/Master/Tree/Basic-Concept/TTL-Delete.md @@ -26,7 +26,7 @@ IoTDB supports device-level TTL settings, which means it is able to delete old d The default unit of TTL is milliseconds. If the time precision in the configuration file changes to another, the TTL is still set to milliseconds. -When setting TTL, the system will look for all devices included in the set path and set TTL for these devices. The system will delete expired data at the device granularity. +When setting TTL, the system will look for all devices included in the set path and set TTL for these devices. The system will delete expired data at the device granularity. The expiration check here is based on the data point timestamp, not the write time. After the device data expires, it will not be queryable. The data in the disk file cannot be guaranteed to be deleted immediately, but it can be guaranteed to be deleted eventually. However, due to operational costs, the expired data will not be physically deleted right after expiring. The physical deletion is delayed until compaction. Therefore, before the data is physically deleted, if the TTL is reduced or lifted, it may cause data that was previously invisible due to TTL to reappear. diff --git a/src/UserGuide/V1.3.x/Basic-Concept/Operate-Metadata_apache.md b/src/UserGuide/V1.3.x/Basic-Concept/Operate-Metadata_apache.md index 9c6df0895..58f0b5c9b 100644 --- a/src/UserGuide/V1.3.x/Basic-Concept/Operate-Metadata_apache.md +++ b/src/UserGuide/V1.3.x/Basic-Concept/Operate-Metadata_apache.md @@ -248,7 +248,7 @@ IoTDB supports device-level TTL settings, which means it is able to delete old d The default unit of TTL is milliseconds. If the time precision in the configuration file changes to another, the TTL is still set to milliseconds. -When setting TTL, the system will look for all devices included in the set path and set TTL for these devices. The system will delete expired data at the device granularity. +When setting TTL, the system will look for all devices included in the set path and set TTL for these devices. The system will delete expired data at the device granularity. The expiration check here is based on the data point timestamp, not the write time. After the device data expires, it will not be queryable. The data in the disk file cannot be guaranteed to be deleted immediately, but it can be guaranteed to be deleted eventually. However, due to operational costs, the expired data will not be physically deleted right after expiring. The physical deletion is delayed until compaction. Therefore, before the data is physically deleted, if the TTL is reduced or lifted, it may cause data that was previously invisible due to TTL to reappear. diff --git a/src/UserGuide/V1.3.x/Basic-Concept/Operate-Metadata_timecho.md b/src/UserGuide/V1.3.x/Basic-Concept/Operate-Metadata_timecho.md index ba687bdab..d3bc3aa5b 100644 --- a/src/UserGuide/V1.3.x/Basic-Concept/Operate-Metadata_timecho.md +++ b/src/UserGuide/V1.3.x/Basic-Concept/Operate-Metadata_timecho.md @@ -248,7 +248,7 @@ IoTDB supports device-level TTL settings, which means it is able to delete old d The default unit of TTL is milliseconds. If the time precision in the configuration file changes to another, the TTL is still set to milliseconds. -When setting TTL, the system will look for all devices included in the set path and set TTL for these devices. The system will delete expired data at the device granularity. +When setting TTL, the system will look for all devices included in the set path and set TTL for these devices. The system will delete expired data at the device granularity. The expiration check here is based on the data point timestamp, not the write time. After the device data expires, it will not be queryable. The data in the disk file cannot be guaranteed to be deleted immediately, but it can be guaranteed to be deleted eventually. However, due to operational costs, the expired data will not be physically deleted right after expiring. The physical deletion is delayed until compaction. Therefore, before the data is physically deleted, if the TTL is reduced or lifted, it may cause data that was previously invisible due to TTL to reappear. diff --git a/src/UserGuide/V1.3.x/Basic-Concept/TTL-Delete.md b/src/UserGuide/V1.3.x/Basic-Concept/TTL-Delete.md index 467922752..dcdcacc77 100644 --- a/src/UserGuide/V1.3.x/Basic-Concept/TTL-Delete.md +++ b/src/UserGuide/V1.3.x/Basic-Concept/TTL-Delete.md @@ -26,7 +26,7 @@ IoTDB supports device-level TTL settings, which means it is able to delete old d The default unit of TTL is milliseconds. If the time precision in the configuration file changes to another, the TTL is still set to milliseconds. -When setting TTL, the system will look for all devices included in the set path and set TTL for these devices. The system will delete expired data at the device granularity. +When setting TTL, the system will look for all devices included in the set path and set TTL for these devices. The system will delete expired data at the device granularity.The expiration check here is based on the data point timestamp, not the write time. After the device data expires, it will not be queryable. The data in the disk file cannot be guaranteed to be deleted immediately, but it can be guaranteed to be deleted eventually. However, due to operational costs, the expired data will not be physically deleted right after expiring. The physical deletion is delayed until compaction. Therefore, before the data is physically deleted, if the TTL is reduced or lifted, it may cause data that was previously invisible due to TTL to reappear. diff --git a/src/UserGuide/dev-1.3/Basic-Concept/Operate-Metadata_apache.md b/src/UserGuide/dev-1.3/Basic-Concept/Operate-Metadata_apache.md index 6673a1d31..cb71ebdd6 100644 --- a/src/UserGuide/dev-1.3/Basic-Concept/Operate-Metadata_apache.md +++ b/src/UserGuide/dev-1.3/Basic-Concept/Operate-Metadata_apache.md @@ -248,7 +248,7 @@ IoTDB supports device-level TTL settings, which means it is able to delete old d The default unit of TTL is milliseconds. If the time precision in the configuration file changes to another, the TTL is still set to milliseconds. -When setting TTL, the system will look for all devices included in the set path and set TTL for these devices. The system will delete expired data at the device granularity. +When setting TTL, the system will look for all devices included in the set path and set TTL for these devices. The system will delete expired data at the device granularity. The expiration check here is based on the data point timestamp, not the write time. After the device data expires, it will not be queryable. The data in the disk file cannot be guaranteed to be deleted immediately, but it can be guaranteed to be deleted eventually. However, due to operational costs, the expired data will not be physically deleted right after expiring. The physical deletion is delayed until compaction. Therefore, before the data is physically deleted, if the TTL is reduced or lifted, it may cause data that was previously invisible due to TTL to reappear. diff --git a/src/UserGuide/dev-1.3/Basic-Concept/Operate-Metadata_timecho.md b/src/UserGuide/dev-1.3/Basic-Concept/Operate-Metadata_timecho.md index ba687bdab..d3bc3aa5b 100644 --- a/src/UserGuide/dev-1.3/Basic-Concept/Operate-Metadata_timecho.md +++ b/src/UserGuide/dev-1.3/Basic-Concept/Operate-Metadata_timecho.md @@ -248,7 +248,7 @@ IoTDB supports device-level TTL settings, which means it is able to delete old d The default unit of TTL is milliseconds. If the time precision in the configuration file changes to another, the TTL is still set to milliseconds. -When setting TTL, the system will look for all devices included in the set path and set TTL for these devices. The system will delete expired data at the device granularity. +When setting TTL, the system will look for all devices included in the set path and set TTL for these devices. The system will delete expired data at the device granularity. The expiration check here is based on the data point timestamp, not the write time. After the device data expires, it will not be queryable. The data in the disk file cannot be guaranteed to be deleted immediately, but it can be guaranteed to be deleted eventually. However, due to operational costs, the expired data will not be physically deleted right after expiring. The physical deletion is delayed until compaction. Therefore, before the data is physically deleted, if the TTL is reduced or lifted, it may cause data that was previously invisible due to TTL to reappear. diff --git a/src/UserGuide/dev-1.3/Basic-Concept/TTL-Delete.md b/src/UserGuide/dev-1.3/Basic-Concept/TTL-Delete.md index 467922752..3b8184168 100644 --- a/src/UserGuide/dev-1.3/Basic-Concept/TTL-Delete.md +++ b/src/UserGuide/dev-1.3/Basic-Concept/TTL-Delete.md @@ -26,7 +26,7 @@ IoTDB supports device-level TTL settings, which means it is able to delete old d The default unit of TTL is milliseconds. If the time precision in the configuration file changes to another, the TTL is still set to milliseconds. -When setting TTL, the system will look for all devices included in the set path and set TTL for these devices. The system will delete expired data at the device granularity. +When setting TTL, the system will look for all devices included in the set path and set TTL for these devices. The system will delete expired data at the device granularity. The expiration check here is based on the data point timestamp, not the write time. After the device data expires, it will not be queryable. The data in the disk file cannot be guaranteed to be deleted immediately, but it can be guaranteed to be deleted eventually. However, due to operational costs, the expired data will not be physically deleted right after expiring. The physical deletion is delayed until compaction. Therefore, before the data is physically deleted, if the TTL is reduced or lifted, it may cause data that was previously invisible due to TTL to reappear. diff --git a/src/UserGuide/latest-Table/Basic-Concept/TTL-Delete-Data.md b/src/UserGuide/latest-Table/Basic-Concept/TTL-Delete-Data.md index be7619140..7cc533f63 100644 --- a/src/UserGuide/latest-Table/Basic-Concept/TTL-Delete-Data.md +++ b/src/UserGuide/latest-Table/Basic-Concept/TTL-Delete-Data.md @@ -32,6 +32,7 @@ TTL values are specified in milliseconds, and once data exceeds its defined life 1. TTL defines the expiration time of data in milliseconds, independent of the time precision configuration file. 2. Modifying TTL settings can cause temporary variations in data accessibility. 3. The system eventually removes expired data, though this process may involve some delay.。 +4. The TTL expiration check is based on the data point timestamp, not the write time. ## 2. Set TTL diff --git a/src/UserGuide/latest/Basic-Concept/Operate-Metadata_apache.md b/src/UserGuide/latest/Basic-Concept/Operate-Metadata_apache.md index 27d1e83d7..45beb7be2 100644 --- a/src/UserGuide/latest/Basic-Concept/Operate-Metadata_apache.md +++ b/src/UserGuide/latest/Basic-Concept/Operate-Metadata_apache.md @@ -248,7 +248,7 @@ IoTDB supports device-level TTL settings, which means it is able to delete old d The default unit of TTL is milliseconds. If the time precision in the configuration file changes to another, the TTL is still set to milliseconds. -When setting TTL, the system will look for all devices included in the set path and set TTL for these devices. The system will delete expired data at the device granularity. +When setting TTL, the system will look for all devices included in the set path and set TTL for these devices. The system will delete expired data at the device granularity. The expiration check here is based on the data point timestamp, not the write time. After the device data expires, it will not be queryable. The data in the disk file cannot be guaranteed to be deleted immediately, but it can be guaranteed to be deleted eventually. However, due to operational costs, the expired data will not be physically deleted right after expiring. The physical deletion is delayed until compaction. Therefore, before the data is physically deleted, if the TTL is reduced or lifted, it may cause data that was previously invisible due to TTL to reappear. diff --git a/src/UserGuide/latest/Basic-Concept/Operate-Metadata_timecho.md b/src/UserGuide/latest/Basic-Concept/Operate-Metadata_timecho.md index c73fe07bd..f60bf49ac 100644 --- a/src/UserGuide/latest/Basic-Concept/Operate-Metadata_timecho.md +++ b/src/UserGuide/latest/Basic-Concept/Operate-Metadata_timecho.md @@ -248,7 +248,7 @@ IoTDB supports device-level TTL settings, which means it is able to delete old d The default unit of TTL is milliseconds. If the time precision in the configuration file changes to another, the TTL is still set to milliseconds. -When setting TTL, the system will look for all devices included in the set path and set TTL for these devices. The system will delete expired data at the device granularity. +When setting TTL, the system will look for all devices included in the set path and set TTL for these devices. The system will delete expired data at the device granularity. The expiration check here is based on the data point timestamp, not the write time. After the device data expires, it will not be queryable. The data in the disk file cannot be guaranteed to be deleted immediately, but it can be guaranteed to be deleted eventually. However, due to operational costs, the expired data will not be physically deleted right after expiring. The physical deletion is delayed until compaction. Therefore, before the data is physically deleted, if the TTL is reduced or lifted, it may cause data that was previously invisible due to TTL to reappear. diff --git a/src/UserGuide/latest/Basic-Concept/TTL-Delete.md b/src/UserGuide/latest/Basic-Concept/TTL-Delete.md index 14b479fe2..97aa8380f 100644 --- a/src/UserGuide/latest/Basic-Concept/TTL-Delete.md +++ b/src/UserGuide/latest/Basic-Concept/TTL-Delete.md @@ -26,7 +26,7 @@ IoTDB supports device-level TTL settings, which means it is able to delete old d The default unit of TTL is milliseconds. If the time precision in the configuration file changes to another, the TTL is still set to milliseconds. -When setting TTL, the system will look for all devices included in the set path and set TTL for these devices. The system will delete expired data at the device granularity. +When setting TTL, the system will look for all devices included in the set path and set TTL for these devices. The system will delete expired data at the device granularity. The expiration check here is based on the data point timestamp, not the write time. After the device data expires, it will not be queryable. The data in the disk file cannot be guaranteed to be deleted immediately, but it can be guaranteed to be deleted eventually. However, due to operational costs, the expired data will not be physically deleted right after expiring. The physical deletion is delayed until compaction. Therefore, before the data is physically deleted, if the TTL is reduced or lifted, it may cause data that was previously invisible due to TTL to reappear. diff --git a/src/zh/UserGuide/Master/Table/Basic-Concept/TTL-Delete-Data.md b/src/zh/UserGuide/Master/Table/Basic-Concept/TTL-Delete-Data.md index c31c23478..9c9f3178d 100644 --- a/src/zh/UserGuide/Master/Table/Basic-Concept/TTL-Delete-Data.md +++ b/src/zh/UserGuide/Master/Table/Basic-Concept/TTL-Delete-Data.md @@ -30,6 +30,7 @@ IoTDB支持对表（table）级别设置数据保留时间（TTL），允许系 1. TTL设置为毫秒，不受配置文件时间精度影响。 2. TTL变更可能影响数据的可查询性。 3. 系统最终会移除过期数据，但存在延迟。 +4. TTL 判断数据是否过期依据的是数据点时间，非写入时间。 ## 2. 设置 TTL diff --git a/src/zh/UserGuide/Master/Tree/Basic-Concept/Operate-Metadata_apache.md b/src/zh/UserGuide/Master/Tree/Basic-Concept/Operate-Metadata_apache.md index 5db4d4be5..eabf9a231 100644 --- a/src/zh/UserGuide/Master/Tree/Basic-Concept/Operate-Metadata_apache.md +++ b/src/zh/UserGuide/Master/Tree/Basic-Concept/Operate-Metadata_apache.md @@ -151,7 +151,7 @@ IoTDB 支持对 device 级别设置数据保留时间（TTL），这使得 IoTDB TTL的默认单位为毫秒，如果配置文件中的时间精度修改为其他单位，设置ttl时仍然使用毫秒单位。 -当设置 TTL 时，系统会根据设置的路径寻找所包含的所有 device，并为这些 device 设置 TTL 时间，系统会按设备粒度对过期数据进行删除。 +当设置 TTL 时，系统会根据设置的路径寻找所包含的所有 device，并为这些 device 设置 TTL 时间，系统会按设备粒度对过期数据进行删除。请注意，此处是否过期判断依据的是数据点时间，不是写入时间。 当设备数据过期后，将不能被查询到，但磁盘文件中的数据不能保证立即删除（会在一定时间内删除），但可以保证最终被删除。 考虑到操作代价，系统不会立即物理删除超过 TTL 的数据，而是通过合并来延迟地物理删除。因此，在数据被物理删除前，如果调小或者解除 TTL，可能会导致之前因 TTL 而不可见的数据重新出现。 系统中仅能设置至多 1000 条 TTL 规则，达到该上限时，需要先删除部分 TTL 规则才能设置新的规则 diff --git a/src/zh/UserGuide/Master/Tree/Basic-Concept/Operate-Metadata_timecho.md b/src/zh/UserGuide/Master/Tree/Basic-Concept/Operate-Metadata_timecho.md index 88c335a69..ad752790f 100644 --- a/src/zh/UserGuide/Master/Tree/Basic-Concept/Operate-Metadata_timecho.md +++ b/src/zh/UserGuide/Master/Tree/Basic-Concept/Operate-Metadata_timecho.md @@ -151,7 +151,7 @@ IoTDB 支持对 device 级别设置数据保留时间（TTL），这使得 IoTDB TTL的默认单位为毫秒，如果配置文件中的时间精度修改为其他单位，设置ttl时仍然使用毫秒单位。 -当设置 TTL 时，系统会根据设置的路径寻找所包含的所有 device，并为这些 device 设置 TTL 时间，系统会按设备粒度对过期数据进行删除。 +当设置 TTL 时，系统会根据设置的路径寻找所包含的所有 device，并为这些 device 设置 TTL 时间，系统会按设备粒度对过期数据进行删除。请注意，此处是否过期判断依据的是数据点时间，不是写入时间。 当设备数据过期后，将不能被查询到，但磁盘文件中的数据不能保证立即删除（会在一定时间内删除），但可以保证最终被删除。 考虑到操作代价，系统不会立即物理删除超过 TTL 的数据，而是通过合并来延迟地物理删除。因此，在数据被物理删除前，如果调小或者解除 TTL，可能会导致之前因 TTL 而不可见的数据重新出现。 系统中仅能设置至多 1000 条 TTL 规则，达到该上限时，需要先删除部分 TTL 规则才能设置新的规则 diff --git a/src/zh/UserGuide/Master/Tree/Basic-Concept/TTL-Delete.md b/src/zh/UserGuide/Master/Tree/Basic-Concept/TTL-Delete.md index 7f321de4a..205eeb9af 100644 --- a/src/zh/UserGuide/Master/Tree/Basic-Concept/TTL-Delete.md +++ b/src/zh/UserGuide/Master/Tree/Basic-Concept/TTL-Delete.md @@ -26,7 +26,7 @@ IoTDB 支持对 device 级别设置数据保留时间（TTL），这使得 IoTDB TTL的默认单位为毫秒，如果配置文件中的时间精度修改为其他单位，设置ttl时仍然使用毫秒单位。 -当设置 TTL 时，系统会根据设置的路径寻找所包含的所有 device，并为这些 device 设置 TTL 时间，系统会按设备粒度对过期数据进行删除。 +当设置 TTL 时，系统会根据设置的路径寻找所包含的所有 device，并为这些 device 设置 TTL 时间，系统会按设备粒度对过期数据进行删除。请注意，此处是否过期判断依据的是数据点时间，不是写入时间。 当设备数据过期后，将不能被查询到，但磁盘文件中的数据不能保证立即删除（会在一定时间内删除），但可以保证最终被删除。 考虑到操作代价，系统不会立即物理删除超过 TTL 的数据，而是通过合并来延迟地物理删除。因此，在数据被物理删除前，如果调小或者解除 TTL，可能会导致之前因 TTL 而不可见的数据重新出现。 系统中仅能设置至多 1000 条 TTL 规则，达到该上限时，需要先删除部分 TTL 规则才能设置新的规则 diff --git a/src/zh/UserGuide/V1.3.x/Basic-Concept/Operate-Metadata_apache.md b/src/zh/UserGuide/V1.3.x/Basic-Concept/Operate-Metadata_apache.md index 152d37850..25855fc49 100644 --- a/src/zh/UserGuide/V1.3.x/Basic-Concept/Operate-Metadata_apache.md +++ b/src/zh/UserGuide/V1.3.x/Basic-Concept/Operate-Metadata_apache.md @@ -151,7 +151,7 @@ IoTDB 支持对 device 级别设置数据保留时间（TTL），这使得 IoTDB TTL的默认单位为毫秒，如果配置文件中的时间精度修改为其他单位，设置ttl时仍然使用毫秒单位。 -当设置 TTL 时，系统会根据设置的路径寻找所包含的所有 device，并为这些 device 设置 TTL 时间，系统会按设备粒度对过期数据进行删除。 +当设置 TTL 时，系统会根据设置的路径寻找所包含的所有 device，并为这些 device 设置 TTL 时间，系统会按设备粒度对过期数据进行删除。请注意，此处是否过期判断依据的是数据点时间，不是写入时间。 当设备数据过期后，将不能被查询到，但磁盘文件中的数据不能保证立即删除（会在一定时间内删除），但可以保证最终被删除。 考虑到操作代价，系统不会立即物理删除超过 TTL 的数据，而是通过合并来延迟地物理删除。因此，在数据被物理删除前，如果调小或者解除 TTL，可能会导致之前因 TTL 而不可见的数据重新出现。 系统中仅能设置至多 1000 条 TTL 规则，达到该上限时，需要先删除部分 TTL 规则才能设置新的规则 diff --git a/src/zh/UserGuide/V1.3.x/Basic-Concept/Operate-Metadata_timecho.md b/src/zh/UserGuide/V1.3.x/Basic-Concept/Operate-Metadata_timecho.md index 38421cbe6..236bde0cf 100644 --- a/src/zh/UserGuide/V1.3.x/Basic-Concept/Operate-Metadata_timecho.md +++ b/src/zh/UserGuide/V1.3.x/Basic-Concept/Operate-Metadata_timecho.md @@ -150,7 +150,7 @@ IoTDB 支持对 device 级别设置数据保留时间（TTL），这使得 IoTDB TTL的默认单位为毫秒，如果配置文件中的时间精度修改为其他单位，设置ttl时仍然使用毫秒单位。 -当设置 TTL 时，系统会根据设置的路径寻找所包含的所有 device，并为这些 device 设置 TTL 时间，系统会按设备粒度对过期数据进行删除。 +当设置 TTL 时，系统会根据设置的路径寻找所包含的所有 device，并为这些 device 设置 TTL 时间，系统会按设备粒度对过期数据进行删除。请注意，此处是否过期判断依据的是数据点时间，不是写入时间。 当设备数据过期后，将不能被查询到，但磁盘文件中的数据不能保证立即删除（会在一定时间内删除），但可以保证最终被删除。 考虑到操作代价，系统不会立即物理删除超过 TTL 的数据，而是通过合并来延迟地物理删除。因此，在数据被物理删除前，如果调小或者解除 TTL，可能会导致之前因 TTL 而不可见的数据重新出现。 系统中仅能设置至多 1000 条 TTL 规则，达到该上限时，需要先删除部分 TTL 规则才能设置新的规则 diff --git a/src/zh/UserGuide/V1.3.x/Basic-Concept/TTL-Delete.md b/src/zh/UserGuide/V1.3.x/Basic-Concept/TTL-Delete.md index baeb08a9f..9e33e5cbe 100644 --- a/src/zh/UserGuide/V1.3.x/Basic-Concept/TTL-Delete.md +++ b/src/zh/UserGuide/V1.3.x/Basic-Concept/TTL-Delete.md @@ -26,7 +26,7 @@ IoTDB 支持对 device 级别设置数据保留时间（TTL），这使得 IoTDB TTL的默认单位为毫秒，如果配置文件中的时间精度修改为其他单位，设置ttl时仍然使用毫秒单位。 -当设置 TTL 时，系统会根据设置的路径寻找所包含的所有 device，并为这些 device 设置 TTL 时间，系统会按设备粒度对过期数据进行删除。 +当设置 TTL 时，系统会根据设置的路径寻找所包含的所有 device，并为这些 device 设置 TTL 时间，系统会按设备粒度对过期数据进行删除。请注意，此处是否过期判断依据的是数据点时间，不是写入时间。 当设备数据过期后，将不能被查询到，但磁盘文件中的数据不能保证立即删除（会在一定时间内删除），但可以保证最终被删除。 考虑到操作代价，系统不会立即物理删除超过 TTL 的数据，而是通过合并来延迟地物理删除。因此，在数据被物理删除前，如果调小或者解除 TTL，可能会导致之前因 TTL 而不可见的数据重新出现。 系统中仅能设置至多 1000 条 TTL 规则，达到该上限时，需要先删除部分 TTL 规则才能设置新的规则 diff --git a/src/zh/UserGuide/dev-1.3/Basic-Concept/Operate-Metadata_apache.md b/src/zh/UserGuide/dev-1.3/Basic-Concept/Operate-Metadata_apache.md index 152d37850..25855fc49 100644 --- a/src/zh/UserGuide/dev-1.3/Basic-Concept/Operate-Metadata_apache.md +++ b/src/zh/UserGuide/dev-1.3/Basic-Concept/Operate-Metadata_apache.md @@ -151,7 +151,7 @@ IoTDB 支持对 device 级别设置数据保留时间（TTL），这使得 IoTDB TTL的默认单位为毫秒，如果配置文件中的时间精度修改为其他单位，设置ttl时仍然使用毫秒单位。 -当设置 TTL 时，系统会根据设置的路径寻找所包含的所有 device，并为这些 device 设置 TTL 时间，系统会按设备粒度对过期数据进行删除。 +当设置 TTL 时，系统会根据设置的路径寻找所包含的所有 device，并为这些 device 设置 TTL 时间，系统会按设备粒度对过期数据进行删除。请注意，此处是否过期判断依据的是数据点时间，不是写入时间。 当设备数据过期后，将不能被查询到，但磁盘文件中的数据不能保证立即删除（会在一定时间内删除），但可以保证最终被删除。 考虑到操作代价，系统不会立即物理删除超过 TTL 的数据，而是通过合并来延迟地物理删除。因此，在数据被物理删除前，如果调小或者解除 TTL，可能会导致之前因 TTL 而不可见的数据重新出现。 系统中仅能设置至多 1000 条 TTL 规则，达到该上限时，需要先删除部分 TTL 规则才能设置新的规则 diff --git a/src/zh/UserGuide/dev-1.3/Basic-Concept/Operate-Metadata_timecho.md b/src/zh/UserGuide/dev-1.3/Basic-Concept/Operate-Metadata_timecho.md index 38421cbe6..236bde0cf 100644 --- a/src/zh/UserGuide/dev-1.3/Basic-Concept/Operate-Metadata_timecho.md +++ b/src/zh/UserGuide/dev-1.3/Basic-Concept/Operate-Metadata_timecho.md @@ -150,7 +150,7 @@ IoTDB 支持对 device 级别设置数据保留时间（TTL），这使得 IoTDB TTL的默认单位为毫秒，如果配置文件中的时间精度修改为其他单位，设置ttl时仍然使用毫秒单位。 -当设置 TTL 时，系统会根据设置的路径寻找所包含的所有 device，并为这些 device 设置 TTL 时间，系统会按设备粒度对过期数据进行删除。 +当设置 TTL 时，系统会根据设置的路径寻找所包含的所有 device，并为这些 device 设置 TTL 时间，系统会按设备粒度对过期数据进行删除。请注意，此处是否过期判断依据的是数据点时间，不是写入时间。 当设备数据过期后，将不能被查询到，但磁盘文件中的数据不能保证立即删除（会在一定时间内删除），但可以保证最终被删除。 考虑到操作代价，系统不会立即物理删除超过 TTL 的数据，而是通过合并来延迟地物理删除。因此，在数据被物理删除前，如果调小或者解除 TTL，可能会导致之前因 TTL 而不可见的数据重新出现。 系统中仅能设置至多 1000 条 TTL 规则，达到该上限时，需要先删除部分 TTL 规则才能设置新的规则 diff --git a/src/zh/UserGuide/dev-1.3/Basic-Concept/TTL-Delete.md b/src/zh/UserGuide/dev-1.3/Basic-Concept/TTL-Delete.md index 45a61ae01..ac6ad94f2 100644 --- a/src/zh/UserGuide/dev-1.3/Basic-Concept/TTL-Delete.md +++ b/src/zh/UserGuide/dev-1.3/Basic-Concept/TTL-Delete.md @@ -26,7 +26,7 @@ IoTDB 支持对 device 级别设置数据保留时间（TTL），这使得 IoTDB TTL的默认单位为毫秒，如果配置文件中的时间精度修改为其他单位，设置ttl时仍然使用毫秒单位。 -当设置 TTL 时，系统会根据设置的路径寻找所包含的所有 device，并为这些 device 设置 TTL 时间，系统会按设备粒度对过期数据进行删除。 +当设置 TTL 时，系统会根据设置的路径寻找所包含的所有 device，并为这些 device 设置 TTL 时间，系统会按设备粒度对过期数据进行删除。请注意，此处是否过期判断依据的是数据点时间，不是写入时间。 当设备数据过期后，将不能被查询到，但磁盘文件中的数据不能保证立即删除（会在一定时间内删除），但可以保证最终被删除。 考虑到操作代价，系统不会立即物理删除超过 TTL 的数据，而是通过合并来延迟地物理删除。因此，在数据被物理删除前，如果调小或者解除 TTL，可能会导致之前因 TTL 而不可见的数据重新出现。 系统中仅能设置至多 1000 条 TTL 规则，达到该上限时，需要先删除部分 TTL 规则才能设置新的规则 diff --git a/src/zh/UserGuide/latest-Table/Basic-Concept/TTL-Delete-Data.md b/src/zh/UserGuide/latest-Table/Basic-Concept/TTL-Delete-Data.md index c31c23478..9c9f3178d 100644 --- a/src/zh/UserGuide/latest-Table/Basic-Concept/TTL-Delete-Data.md +++ b/src/zh/UserGuide/latest-Table/Basic-Concept/TTL-Delete-Data.md @@ -30,6 +30,7 @@ IoTDB支持对表（table）级别设置数据保留时间（TTL），允许系 1. TTL设置为毫秒，不受配置文件时间精度影响。 2. TTL变更可能影响数据的可查询性。 3. 系统最终会移除过期数据，但存在延迟。 +4. TTL 判断数据是否过期依据的是数据点时间，非写入时间。 ## 2. 设置 TTL diff --git a/src/zh/UserGuide/latest/Basic-Concept/Operate-Metadata_apache.md b/src/zh/UserGuide/latest/Basic-Concept/Operate-Metadata_apache.md index 08f1509da..d71630991 100644 --- a/src/zh/UserGuide/latest/Basic-Concept/Operate-Metadata_apache.md +++ b/src/zh/UserGuide/latest/Basic-Concept/Operate-Metadata_apache.md @@ -152,7 +152,7 @@ IoTDB 支持对 device 级别设置数据保留时间（TTL），这使得 IoTDB TTL的默认单位为毫秒，如果配置文件中的时间精度修改为其他单位，设置ttl时仍然使用毫秒单位。 -当设置 TTL 时，系统会根据设置的路径寻找所包含的所有 device，并为这些 device 设置 TTL 时间，系统会按设备粒度对过期数据进行删除。 +当设置 TTL 时，系统会根据设置的路径寻找所包含的所有 device，并为这些 device 设置 TTL 时间，系统会按设备粒度对过期数据进行删除。请注意，此处是否过期判断依据的是数据点时间，不是写入时间。 当设备数据过期后，将不能被查询到，但磁盘文件中的数据不能保证立即删除（会在一定时间内删除），但可以保证最终被删除。 考虑到操作代价，系统不会立即物理删除超过 TTL 的数据，而是通过合并来延迟地物理删除。因此，在数据被物理删除前，如果调小或者解除 TTL，可能会导致之前因 TTL 而不可见的数据重新出现。 系统中仅能设置至多 1000 条 TTL 规则，达到该上限时，需要先删除部分 TTL 规则才能设置新的规则 diff --git a/src/zh/UserGuide/latest/Basic-Concept/Operate-Metadata_timecho.md b/src/zh/UserGuide/latest/Basic-Concept/Operate-Metadata_timecho.md index 013fa0ba0..052fd164e 100644 --- a/src/zh/UserGuide/latest/Basic-Concept/Operate-Metadata_timecho.md +++ b/src/zh/UserGuide/latest/Basic-Concept/Operate-Metadata_timecho.md @@ -151,7 +151,7 @@ IoTDB 支持对 device 级别设置数据保留时间（TTL），这使得 IoTDB TTL的默认单位为毫秒，如果配置文件中的时间精度修改为其他单位，设置ttl时仍然使用毫秒单位。 -当设置 TTL 时，系统会根据设置的路径寻找所包含的所有 device，并为这些 device 设置 TTL 时间，系统会按设备粒度对过期数据进行删除。 +当设置 TTL 时，系统会根据设置的路径寻找所包含的所有 device，并为这些 device 设置 TTL 时间，系统会按设备粒度对过期数据进行删除。请注意，此处是否过期判断依据的是数据点时间，不是写入时间。 当设备数据过期后，将不能被查询到，但磁盘文件中的数据不能保证立即删除（会在一定时间内删除），但可以保证最终被删除。 考虑到操作代价，系统不会立即物理删除超过 TTL 的数据，而是通过合并来延迟地物理删除。因此，在数据被物理删除前，如果调小或者解除 TTL，可能会导致之前因 TTL 而不可见的数据重新出现。 系统中仅能设置至多 1000 条 TTL 规则，达到该上限时，需要先删除部分 TTL 规则才能设置新的规则 diff --git a/src/zh/UserGuide/latest/Basic-Concept/TTL-Delete.md b/src/zh/UserGuide/latest/Basic-Concept/TTL-Delete.md index 7f321de4a..205eeb9af 100644 --- a/src/zh/UserGuide/latest/Basic-Concept/TTL-Delete.md +++ b/src/zh/UserGuide/latest/Basic-Concept/TTL-Delete.md @@ -26,7 +26,7 @@ IoTDB 支持对 device 级别设置数据保留时间（TTL），这使得 IoTDB TTL的默认单位为毫秒，如果配置文件中的时间精度修改为其他单位，设置ttl时仍然使用毫秒单位。 -当设置 TTL 时，系统会根据设置的路径寻找所包含的所有 device，并为这些 device 设置 TTL 时间，系统会按设备粒度对过期数据进行删除。 +当设置 TTL 时，系统会根据设置的路径寻找所包含的所有 device，并为这些 device 设置 TTL 时间，系统会按设备粒度对过期数据进行删除。请注意，此处是否过期判断依据的是数据点时间，不是写入时间。 当设备数据过期后，将不能被查询到，但磁盘文件中的数据不能保证立即删除（会在一定时间内删除），但可以保证最终被删除。 考虑到操作代价，系统不会立即物理删除超过 TTL 的数据，而是通过合并来延迟地物理删除。因此，在数据被物理删除前，如果调小或者解除 TTL，可能会导致之前因 TTL 而不可见的数据重新出现。 系统中仅能设置至多 1000 条 TTL 规则，达到该上限时，需要先删除部分 TTL 规则才能设置新的规则