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TDengine

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Merge pull request #17301 from taosdata/docs/query_doc_wxy 

docs: add super table tag query method. add keyword description to system table column
上级 c79fd325 dc9f535b
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docs/en/12-taos-sql/04-stable.md
浏览文件 @ c940cbdb
......@@ -49,6 +49,55 @@ The preceding SQL statement can be used in migration scenarios. It returns the C
DESCRIBE [db_name.]stb_name;
```
### View tag information for all child tables in the supertable
```
taos> SHOW TABLE TAGS FROM st1;
tbname | id | loc |
======================================================================
st1s1 | 1 | beijing |
st1s2 | 2 | shanghai |
st1s3 | 3 | guangzhou |
Query OK, 3 rows in database (0.004455s)
```
The first column of the returned result set is the subtable name, and the subsequent columns are the tag columns.
If you already know the name of the tag column, you can use the following statement to get the value of the specified tag column.
```
taos> SELECT DISTINCT TBNAME, id FROM st1;
tbname | id |
===============================================
st1s1 | 1 |
st1s2 | 2 |
st1s3 | 3 |
Query OK, 3 rows in database (0.002891s)
```
It should be noted that DISTINCT and TBNAME in the SELECT statement are essential, and TDengine will optimize the statement according to them, so that it can return the tag value correctly and quickly even when there is no data or a lot of data.
### View the tag information of a subtable
```
taos> SHOW TAGS FROM st1s1;
table_name | db_name | stable_name | tag_name | tag_type | tag_value |
============================================================================================================
st1s1 | test | st1 | id | INT | 1 |
st1s1 | test | st1 | loc | VARCHAR(20) | beijing |
Query OK, 2 rows in database (0.003684s)
```
Similarly, you can also use the SELECT statement to query the value of the specified tag column.
```
taos> SELECT DISTINCT TBNAME, id, loc FROM st1s1;
tbname | id | loc |
==================================================
st1s1 | 1 | beijing |
Query OK, 1 rows in database (0.001884s)
```
## Drop STable
```
......
docs/en/12-taos-sql/22-meta.md
浏览文件 @ c940cbdb
......@@ -29,8 +29,8 @@ Provides information about dnodes. Similar to SHOW DNODES.
| # | **Column** | **Data Type** | **Description** |
| --- | :------------: | ------------ | ------------------------- |
| 1 | vnodes | SMALLINT | Current number of vnodes on the dnode |
| 2 | vnodes | SMALLINT | Maximum number of vnodes on the dnode |
| 1 | vnodes | SMALLINT | Current number of vnodes on the dnode. It should be noted that `vnodes` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 2 | support_vnodes | SMALLINT | Maximum number of vnodes on the dnode |
| 3 | status | BINARY(10) | Current status |
| 4 | note | BINARY(256) | Reason for going offline or other information |
| 5 | id | SMALLINT | Dnode ID |
......@@ -49,16 +49,6 @@ Provides information about mnodes. Similar to SHOW MNODES.
| 4 | role_time | TIMESTAMP | Time at which the current role was assumed |
| 5 | create_time | TIMESTAMP | Creation time |
## INS_MODULES
Provides information about modules. Similar to SHOW MODULES.
| # | **Column** | **Data Type** | **Description** |
| --- | :------: | ------------ | ---------- |
| 1 | id | SMALLINT | Module ID |
| 2 | endpoint | BINARY(134) | Module endpoint |
| 3 | module | BINARY(10) | Module status |
## INS_QNODES
Provides information about qnodes. Similar to SHOW QNODES.
......@@ -88,33 +78,33 @@ Provides information about user-created databases. Similar to SHOW DATABASES.
| 1| name| BINARY(32)| Database name |
| 2 | create_time | TIMESTAMP | Creation time |
| 3 | ntables | INT | Number of standard tables and subtables (not including supertables) |
| 4 | vgroups | INT | Number of vgroups |
| 6 | replica | INT | Number of replicas |
| 7 | quorum | BINARY(3) | Strong consistency |
| 8 | duration | INT | Duration for storage of single files |
| 9 | keep | INT | Data retention period |
| 10 | buffer | INT | Write cache size per vnode, in MB |
| 11 | pagesize | INT | Page size for vnode metadata storage engine, in KB |
| 12 | pages | INT | Number of pages per vnode metadata storage engine |
| 13 | minrows | INT | Maximum number of records per file block |
| 14 | maxrows | INT | Minimum number of records per file block |
| 15 | comp | INT | Compression method |
| 16 | precision | BINARY(2) | Time precision |
| 4 | vgroups | INT | Number of vgroups. It should be noted that `vnodes` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 6 | replica | INT | Number of replicas. It should be noted that `replica` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 7 | strict | BINARY(3) | Strong consistency. It should be noted that `strict` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 8 | duration | INT | Duration for storage of single files. It should be noted that `duration` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 9 | keep | INT | Data retention period. It should be noted that `keep` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 10 | buffer | INT | Write cache size per vnode, in MB. It should be noted that `buffer` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 11 | pagesize | INT | Page size for vnode metadata storage engine, in KB. It should be noted that `pagesize` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 12 | pages | INT | Number of pages per vnode metadata storage engine. It should be noted that `pages` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 13 | minrows | INT | Maximum number of records per file block. It should be noted that `minrows` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 14 | maxrows | INT | Minimum number of records per file block. It should be noted that `maxrows` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 15 | comp | INT | Compression method. It should be noted that `comp` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 16 | precision | BINARY(2) | Time precision. It should be noted that `precision` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 17 | status | BINARY(10) | Current database status |
| 18 | retention | BINARY (60) | Aggregation interval and retention period |
| 19 | single_stable | BOOL | Whether the database can contain multiple supertables |
| 20 | cachemodel | BINARY(60) | Caching method for the newest data |
| 21 | cachesize | INT | Memory per vnode used for caching the newest data |
| 22 | wal_level | INT | WAL level |
| 23 | wal_fsync_period | INT | Interval at which WAL is written to disk |
| 24 | wal_retention_period | INT | WAL retention period |
| 25 | wal_retention_size | INT | Maximum WAL size |
| 26 | wal_roll_period | INT | WAL rotation period |
| 27 | wal_segment_size | BIGINT | WAL file size |
| 28 | stt_trigger | SMALLINT | The threshold for number of files to trigger file merging |
| 29 | table_prefix | SMALLINT | The prefix length in the table name that is ignored when distributing table to vnode based on table name |
| 30 | table_suffix | SMALLINT | The suffix length in the table name that is ignored when distributing table to vnode based on table name |
| 31 | tsdb_pagesize | INT | The page size for internal storage engine, its unit is KB |
| 18 | retentions | BINARY (60) | Aggregation interval and retention period. It should be noted that `retentions` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 19 | single_stable | BOOL | Whether the database can contain multiple supertables. It should be noted that `single_stable` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 20 | cachemodel | BINARY(60) | Caching method for the newest data. It should be noted that `cachemodel` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 21 | cachesize | INT | Memory per vnode used for caching the newest data. It should be noted that `cachesize` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 22 | wal_level | INT | WAL level. It should be noted that `wal_level` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 23 | wal_fsync_period | INT | Interval at which WAL is written to disk. It should be noted that `wal_fsync_period` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 24 | wal_retention_period | INT | WAL retention period. It should be noted that `wal_retention_period` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 25 | wal_retention_size | INT | Maximum WAL size. It should be noted that `wal_retention_size` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 26 | wal_roll_period | INT | WAL rotation period. It should be noted that `wal_roll_period` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 27 | wal_segment_size | BIGINT | WAL file size. It should be noted that `wal_segment_size` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 28 | stt_trigger | SMALLINT | The threshold for number of files to trigger file merging. It should be noted that `stt_trigger` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 29 | table_prefix | SMALLINT | The prefix length in the table name that is ignored when distributing table to vnode based on table name. It should be noted that `table_prefix` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 30 | table_suffix | SMALLINT | The suffix length in the table name that is ignored when distributing table to vnode based on table name. It should be noted that `table_suffix` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 31 | tsdb_pagesize | INT | The page size for internal storage engine, its unit is KB. It should be noted that `tsdb_pagesize` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
## INS_FUNCTIONS
......@@ -123,8 +113,8 @@ Provides information about user-defined functions.
| # | **Column** | **Data Type** | **Description** |
| --- | :---------: | ------------ | -------------- |
| 1 | name | BINARY(64) | Function name |
| 2 | comment | BINARY(255) | Function description |
| 3 | aggregate | INT | Whether the UDF is an aggregate function |
| 2 | comment | BINARY(255) | Function description. It should be noted that `comment` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 3 | aggregate | INT | Whether the UDF is an aggregate function. It should be noted that `aggregate` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 4 | output_type | BINARY(31) | Output data type |
| 5 | create_time | TIMESTAMP | Creation time |
| 6 | code_len | INT | Length of the source code |
......@@ -153,12 +143,12 @@ Provides information about supertables.
| 2 | db_name | BINARY(64) | All databases in the supertable |
| 3 | create_time | TIMESTAMP | Creation time |
| 4 | columns | INT | Number of columns |
| 5 | tags | INT | Number of tags |
| 5 | tags | INT | Number of tags. It should be noted that `tags` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 6 | last_update | TIMESTAMP | Last updated time |
| 7 | table_comment | BINARY(1024) | Table description |
| 8 | watermark | BINARY(64) | Window closing time |
| 9 | max_delay | BINARY(64) | Maximum delay for pushing stream processing results |
| 10 | rollup | BINARY(128) | Rollup aggregate function |
| 8 | watermark | BINARY(64) | Window closing time. It should be noted that `watermark` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 9 | max_delay | BINARY(64) | Maximum delay for pushing stream processing results. It should be noted that `max_delay` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 10 | rollup | BINARY(128) | Rollup aggregate function. It should be noted that `rollup` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
## INS_TABLES
......@@ -173,7 +163,7 @@ Provides information about standard tables and subtables.
| 5 | stable_name | BINARY(192) | Supertable name |
| 6 | uid | BIGINT | Table ID |
| 7 | vgroup_id | INT | Vgroup ID |
| 8 | ttl | INT | Table time-to-live |
| 8 | ttl | INT | Table time-to-live. It should be noted that `ttl` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 9 | table_comment | BINARY(1024) | Table description |
| 10 | type | BINARY(20) | Table type |
......@@ -206,13 +196,13 @@ Provides information about TDengine Enterprise Edition permissions.
| --- | :---------: | ------------ | -------------------------------------------------- |
| 1 | version | BINARY(9) | Whether the deployment is a licensed or trial version |
| 2 | cpu_cores | BINARY(9) | CPU cores included in license |
| 3 | dnodes | BINARY(10) | Dnodes included in license |
| 4 | streams | BINARY(10) | Streams included in license |
| 5 | users | BINARY(10) | Users included in license |
| 6 | streams | BINARY(10) | Accounts included in license |
| 7 | storage | BINARY(21) | Storage space included in license |
| 8 | connections | BINARY(21) | Client connections included in license |
| 9 | databases | BINARY(11) | Databases included in license |
| 3 | dnodes | BINARY(10) | Dnodes included in license. It should be noted that `dnodes` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 4 | streams | BINARY(10) | Streams included in license. It should be noted that `streams` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 5 | users | BINARY(10) | Users included in license. It should be noted that `users` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 6 | accounts | BINARY(10) | Accounts included in license. It should be noted that `accounts` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 7 | storage | BINARY(21) | Storage space included in license. It should be noted that `storage` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 8 | connections | BINARY(21) | Client connections included in license. It should be noted that `connections` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 9 | databases | BINARY(11) | Databases included in license. It should be noted that `databases` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 10 | speed | BINARY(9) | Write speed specified in license (data points per second) |
| 11 | querytime | BINARY(9) | Total query time specified in license |
| 12 | timeseries | BINARY(21) | Number of metrics included in license |
......@@ -227,7 +217,7 @@ Provides information about vgroups.
| --- | :-------: | ------------ | ------------------------------------------------------ |
| 1 | vgroup_id | INT | Vgroup ID |
| 2 | db_name | BINARY(32) | Database name |
| 3 | tables | INT | Tables in vgroup |
| 3 | tables | INT | Tables in vgroup. It should be noted that `tables` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 4 | status | BINARY(10) | Vgroup status |
| 5 | v1_dnode | INT | Dnode ID of first vgroup member |
| 6 | v1_status | BINARY(10) | Status of first vgroup member |
......@@ -246,7 +236,7 @@ Provides system configuration information.
| # | **Column** | **Data Type** | **Description** |
| --- | :------: | ------------ | ------------ |
| 1 | name | BINARY(32) | Parameter |
| 2 | value | BINARY(64) | Value |
| 2 | value | BINARY(64) | Value. It should be noted that `value` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
## INS_DNODE_VARIABLES
......@@ -256,7 +246,7 @@ Provides dnode configuration information.
| --- | :------: | ------------ | ------------ |
| 1 | dnode_id | INT | Dnode ID |
| 2 | name | BINARY(32) | Parameter |
| 3 | value | BINARY(64) | Value |
| 3 | value | BINARY(64) | Value. It should be noted that `value` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
## INS_TOPICS
......@@ -287,5 +277,5 @@ Provides dnode configuration information.
| 5 | source_db | BINARY(64) | Source database |
| 6 | target_db | BIANRY(64) | Target database |
| 7 | target_table | BINARY(192) | Target table |
| 8 | watermark | BIGINT | Watermark (see stream processing documentation) |
| 9 | trigger | INT | Method of triggering the result push (see stream processing documentation) |
| 8 | watermark | BIGINT | Watermark (see stream processing documentation). It should be noted that `watermark` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 9 | trigger | INT | Method of triggering the result push (see stream processing documentation). It should be noted that `trigger` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
docs/zh/12-taos-sql/04-stable.md
浏览文件 @ c940cbdb
......@@ -50,6 +50,56 @@ SHOW CREATE STABLE stb_name;
DESCRIBE [db_name.]stb_name;
```
### 获取超级表中所有子表的标签信息
```
taos> SHOW TABLE TAGS FROM st1;
tbname | id | loc |
======================================================================
st1s1 | 1 | beijing |
st1s2 | 2 | shanghai |
st1s3 | 3 | guangzhou |
Query OK, 3 rows in database (0.004455s)
```
返回结果集的第一列为子表名，后续列为标签列。
如果已经知道标签列的名称，可以使用下面的语句来获取指定标签列的值。
```
taos> SELECT DISTINCT TBNAME, id FROM st1;
tbname | id |
===============================================
st1s1 | 1 |
st1s2 | 2 |
st1s3 | 3 |
Query OK, 3 rows in database (0.002891s)
```
需要注意，SELECT 语句中的 DISTINCT 和 TBNAME 都是必不可少的，TDengine 会根据它们对语句进行优化，使之在没有数据或数据非常多的情况下都可以正确并快速的返回标签值。
### 获取某个子表的标签信息
```
taos> SHOW TAGS FROM st1s1;
table_name | db_name | stable_name | tag_name | tag_type | tag_value |
============================================================================================================
st1s1 | test | st1 | id | INT | 1 |
st1s1 | test | st1 | loc | VARCHAR(20) | beijing |
Query OK, 2 rows in database (0.003684s)
```
同样的，也可以用 SELECT 语句来查询指定标签列的值。
```
taos> SELECT DISTINCT TBNAME, id, loc FROM st1s1;
tbname | id | loc |
==================================================
st1s1 | 1 | beijing |
Query OK, 1 rows in database (0.001884s)
```
## 删除超级表
```
......
docs/zh/12-taos-sql/22-meta.md
浏览文件 @ c940cbdb
......@@ -30,7 +30,7 @@ TDengine 内置了一个名为 `INFORMATION_SCHEMA` 的数据库，提供对数
| # | **列名** | **数据类型** | **说明** |
| --- | :------------: | ------------ | ------------------------- |
| 1 | vnodes | SMALLINT | dnode 中的实际 vnode 个数 |
| 1 | vnodes | SMALLINT | dnode 中的实际 vnode 个数。需要注意，`vnodes` 为 TDengine 关键字，作为列名使用时需要使用 ` 进行转义。 |
| 2 | support_vnodes | SMALLINT | 最多支持的 vnode 个数 |
| 3 | status | BINARY(10) | 当前状态 |
| 4 | note | BINARY(256) | 离线原因等信息 |
......@@ -50,16 +50,6 @@ TDengine 内置了一个名为 `INFORMATION_SCHEMA` 的数据库，提供对数
| 4 | role_time | TIMESTAMP | 成为当前角色的时间 |
| 5 | create_time | TIMESTAMP | 创建时间 |
## INS_MODULES
提供组件的相关信息。也可以使用 SHOW MODULES 来查询这些信息
| # | **列名** | **数据类型** | **说明** |
| --- | :------: | ------------ | ---------- |
| 1 | id | SMALLINT | module id |
| 2 | endpoint | BINARY(134) | 组件的地址 |
| 3 | module | BINARY(10) | 组件状态 |
## INS_QNODES
当前系统中 QNODE 的信息。也可以使用 SHOW QNODES 来查询这些信息。
......@@ -89,33 +79,33 @@ TDengine 内置了一个名为 `INFORMATION_SCHEMA` 的数据库，提供对数
| 1 | name | BINARY(32) | 数据库名 |
| 2 | create_time | TIMESTAMP | 创建时间 |
| 3 | ntables | INT | 数据库中表的数量，包含子表和普通表但不包含超级表 |
| 4 | vgroups | INT | 数据库中有多少个 vgroup |
| 6 | replica | INT | 副本数 |
| 7 | quorum | BINARY(3) | 强一致性 |
| 8 | duration | INT | 单文件存储数据的时间跨度 |
| 9 | keep | INT | 数据保留时长 |
| 10 | buffer | INT | 每个 vnode 写缓存的内存块大小，单位 MB |
| 11 | pagesize | INT | 每个 VNODE 中元数据存储引擎的页大小，单位为 KB |
| 12 | pages | INT | 每个 vnode 元数据存储引擎的缓存页个数 |
| 13 | minrows | INT | 文件块中记录的最大条数 |
| 14 | maxrows | INT | 文件块中记录的最小条数 |
| 15 | comp | INT | 数据压缩方式 |
| 16 | precision | BINARY(2) | 时间分辨率 |
| 4 | vgroups | INT | 数据库中有多少个 vgroup。需要注意，`vgroups` 为 TDengine 关键字，作为列名使用时需要使用 ` 进行转义。 |
| 6 | replica | INT | 副本数。需要注意，`replica` 为 TDengine 关键字，作为列名使用时需要使用 ` 进行转义。 |
| 7 | strict | BINARY(3) | 强一致性。需要注意，`strict` 为 TDengine 关键字，作为列名使用时需要使用 ` 进行转义。 |
| 8 | duration | INT | 单文件存储数据的时间跨度。需要注意，`duration` 为 TDengine 关键字，作为列名使用时需要使用 ` 进行转义。 |
| 9 | keep | INT | 数据保留时长。需要注意，`keep` 为 TDengine 关键字，作为列名使用时需要使用 ` 进行转义。 |
| 10 | buffer | INT | 每个 vnode 写缓存的内存块大小，单位 MB。需要注意，`buffer` 为 TDengine 关键字，作为列名使用时需要使用 ` 进行转义。 |
| 11 | pagesize | INT | 每个 VNODE 中元数据存储引擎的页大小，单位为 KB。需要注意，`pagesize` 为 TDengine 关键字，作为列名使用时需要使用 ` 进行转义。 |
| 12 | pages | INT | 每个 vnode 元数据存储引擎的缓存页个数。需要注意，`pages` 为 TDengine 关键字，作为列名使用时需要使用 ` 进行转义。 |
| 13 | minrows | INT | 文件块中记录的最大条数。需要注意，`minrows` 为 TDengine 关键字，作为列名使用时需要使用 ` 进行转义。 |
| 14 | maxrows | INT | 文件块中记录的最小条数。需要注意，`maxrows` 为 TDengine 关键字，作为列名使用时需要使用 ` 进行转义。 |
| 15 | comp | INT | 数据压缩方式。需要注意，`comp` 为 TDengine 关键字，作为列名使用时需要使用 ` 进行转义。 |
| 16 | precision | BINARY(2) | 时间分辨率。需要注意，`precision` 为 TDengine 关键字，作为列名使用时需要使用 ` 进行转义。 |
| 17 | status | BINARY(10) | 数据库状态 |
| 18 | retention | BINARY (60) | 数据的聚合周期和保存时长 |
| 19 | single_stable | BOOL | 表示此数据库中是否只可以创建一个超级表 |
| 20 | cachemodel | BINARY(60) | 表示是否在内存中缓存子表的最近数据 |
| 21 | cachesize | INT | 表示每个 vnode 中用于缓存子表最近数据的内存大小 |
| 22 | wal_level | INT | WAL 级别 |
| 23 | wal_fsync_period | INT | 数据落盘周期 |
| 24 | wal_retention_period | INT | WAL 的保存时长 |
| 25 | wal_retention_size | INT | WAL 的保存上限 |
| 26 | wal_roll_period | INT | wal 文件切换时长 |
| 27 | wal_segment_size | BIGINT | wal 单个文件大小 |
| 28 | stt_trigger | SMALLINT | 触发文件合并的落盘文件的个数 |
| 29 | table_prefix | SMALLINT | 内部存储引擎根据表名分配存储该表数据的 VNODE 时要忽略的前缀的长度 |
| 30 | table_suffix | SMALLINT | 内部存储引擎根据表名分配存储该表数据的 VNODE 时要忽略的后缀的长度 |
| 31 | tsdb_pagesize | INT | 时序数据存储引擎中的页大小 |
| 18 | retentions | BINARY (60) | 数据的聚合周期和保存时长。需要注意，`retentions` 为 TDengine 关键字，作为列名使用时需要使用 ` 进行转义。 |
| 19 | single_stable | BOOL | 表示此数据库中是否只可以创建一个超级表。需要注意，`single_stable` 为 TDengine 关键字，作为列名使用时需要使用 ` 进行转义。 |
| 20 | cachemodel | BINARY(60) | 表示是否在内存中缓存子表的最近数据。需要注意，`cachemodel` 为 TDengine 关键字，作为列名使用时需要使用 ` 进行转义。 |
| 21 | cachesize | INT | 表示每个 vnode 中用于缓存子表最近数据的内存大小。需要注意，`cachesize` 为 TDengine 关键字，作为列名使用时需要使用 ` 进行转义。 |
| 22 | wal_level | INT | WAL 级别。需要注意，`wal_level` 为 TDengine 关键字，作为列名使用时需要使用 ` 进行转义。 |
| 23 | wal_fsync_period | INT | 数据落盘周期。需要注意，`wal_fsync_period` 为 TDengine 关键字，作为列名使用时需要使用 ` 进行转义。 |
| 24 | wal_retention_period | INT | WAL 的保存时长。需要注意，`wal_retention_period` 为 TDengine 关键字，作为列名使用时需要使用 ` 进行转义。 |
| 25 | wal_retention_size | INT | WAL 的保存上限。需要注意，`wal_retention_size` 为 TDengine 关键字，作为列名使用时需要使用 ` 进行转义。 |
| 26 | wal_roll_period | INT | wal 文件切换时长。需要注意，`wal_roll_period` 为 TDengine 关键字，作为列名使用时需要使用 ` 进行转义。 |
| 27 | wal_segment_size | BIGINT | wal 单个文件大小。需要注意，`wal_segment_size` 为 TDengine 关键字，作为列名使用时需要使用 ` 进行转义。 |
| 28 | stt_trigger | SMALLINT | 触发文件合并的落盘文件的个数。需要注意，`stt_trigger` 为 TDengine 关键字，作为列名使用时需要使用 ` 进行转义。 |
| 29 | table_prefix | SMALLINT | 内部存储引擎根据表名分配存储该表数据的 VNODE 时要忽略的前缀的长度。需要注意，`table_prefix` 为 TDengine 关键字，作为列名使用时需要使用 ` 进行转义。 |
| 30 | table_suffix | SMALLINT | 内部存储引擎根据表名分配存储该表数据的 VNODE 时要忽略的后缀的长度。需要注意，`table_suffix` 为 TDengine 关键字，作为列名使用时需要使用 ` 进行转义。 |
| 31 | tsdb_pagesize | INT | 时序数据存储引擎中的页大小。需要注意，`tsdb_pagesize` 为 TDengine 关键字，作为列名使用时需要使用 ` 进行转义。 |
## INS_FUNCTIONS
......@@ -124,8 +114,8 @@ TDengine 内置了一个名为 `INFORMATION_SCHEMA` 的数据库，提供对数
| # | **列名** | **数据类型** | **说明** |
| --- | :---------: | ------------ | -------------- |
| 1 | name | BINARY(64) | 函数名 |
| 2 | comment | BINARY(255) | 补充说明 |
| 3 | aggregate | INT | 是否为聚合函数 |
| 2 | comment | BINARY(255) | 补充说明。需要注意，`comment` 为 TDengine 关键字，作为列名使用时需要使用 ` 进行转义。 |
| 3 | aggregate | INT | 是否为聚合函数。需要注意，`aggregate` 为 TDengine 关键字，作为列名使用时需要使用 ` 进行转义。 |
| 4 | output_type | BINARY(31) | 输出类型 |
| 5 | create_time | TIMESTAMP | 创建时间 |
| 6 | code_len | INT | 代码长度 |
......@@ -154,12 +144,12 @@ TDengine 内置了一个名为 `INFORMATION_SCHEMA` 的数据库，提供对数
| 2 | db_name | BINARY(64) | 超级表所在的数据库的名称 |
| 3 | create_time | TIMESTAMP | 创建时间 |
| 4 | columns | INT | 列数目 |
| 5 | tags | INT | 标签数目 |
| 5 | tags | INT | 标签数目。需要注意，`tags` 为 TDengine 关键字，作为列名使用时需要使用 ` 进行转义。 |
| 6 | last_update | TIMESTAMP | 最后更新时间 |
| 7 | table_comment | BINARY(1024) | 表注释 |
| 8 | watermark | BINARY(64) | 窗口的关闭时间 |
| 9 | max_delay | BINARY(64) | 推送计算结果的最大延迟 |
| 10 | rollup | BINARY(128) | rollup 聚合函数 |
| 8 | watermark | BINARY(64) | 窗口的关闭时间。需要注意，`watermark` 为 TDengine 关键字，作为列名使用时需要使用 ` 进行转义。 |
| 9 | max_delay | BINARY(64) | 推送计算结果的最大延迟。需要注意，`max_delay` 为 TDengine 关键字，作为列名使用时需要使用 ` 进行转义。 |
| 10 | rollup | BINARY(128) | rollup 聚合函数。需要注意，`rollup` 为 TDengine 关键字，作为列名使用时需要使用 ` 进行转义。 |
## INS_TABLES
......@@ -174,7 +164,7 @@ TDengine 内置了一个名为 `INFORMATION_SCHEMA` 的数据库，提供对数
| 5 | stable_name | BINARY(192) | 所属的超级表表名 |
| 6 | uid | BIGINT | 表 id |
| 7 | vgroup_id | INT | vgroup id |
| 8 | ttl | INT | 表的生命周期 |
| 8 | ttl | INT | 表的生命周期。需要注意，`ttl` 为 TDengine 关键字，作为列名使用时需要使用 ` 进行转义。 |
| 9 | table_comment | BINARY(1024) | 表注释 |
| 10 | type | BINARY(20) | 表类型 |
......@@ -207,13 +197,13 @@ TDengine 内置了一个名为 `INFORMATION_SCHEMA` 的数据库，提供对数
| --- | :---------: | ------------ | -------------------------------------------------- |
| 1 | version | BINARY(9) | 企业版授权说明：official(官方授权的)/trial(试用的) |
| 2 | cpu_cores | BINARY(9) | 授权使用的 CPU 核心数量 |
| 3 | dnodes | BINARY(10) | 授权使用的 dnode 节点数量 |
| 4 | streams | BINARY(10) | 授权创建的流数量 |
| 5 | users | BINARY(10) | 授权创建的用户数量 |
| 6 | accounts | BINARY(10) | 授权创建的帐户数量 |
| 7 | storage | BINARY(21) | 授权使用的存储空间大小 |
| 8 | connections | BINARY(21) | 授权使用的客户端连接数量 |
| 9 | databases | BINARY(11) | 授权使用的数据库数量 |
| 3 | dnodes | BINARY(10) | 授权使用的 dnode 节点数量。需要注意，`dnodes` 为 TDengine 关键字，作为列名使用时需要使用 ` 进行转义。 |
| 4 | streams | BINARY(10) | 授权创建的流数量。需要注意，`streams` 为 TDengine 关键字，作为列名使用时需要使用 ` 进行转义。 |
| 5 | users | BINARY(10) | 授权创建的用户数量。需要注意，`users` 为 TDengine 关键字，作为列名使用时需要使用 ` 进行转义。 |
| 6 | accounts | BINARY(10) | 授权创建的帐户数量。需要注意，`accounts` 为 TDengine 关键字，作为列名使用时需要使用 ` 进行转义。 |
| 7 | storage | BINARY(21) | 授权使用的存储空间大小。需要注意，`storage` 为 TDengine 关键字，作为列名使用时需要使用 ` 进行转义。 |
| 8 | connections | BINARY(21) | 授权使用的客户端连接数量。需要注意，`connections` 为 TDengine 关键字，作为列名使用时需要使用 ` 进行转义。 |
| 9 | databases | BINARY(11) | 授权使用的数据库数量。需要注意，`databases` 为 TDengine 关键字，作为列名使用时需要使用 ` 进行转义。 |
| 10 | speed | BINARY(9) | 授权使用的数据点每秒写入数量 |
| 11 | querytime | BINARY(9) | 授权使用的查询总时长 |
| 12 | timeseries | BINARY(21) | 授权使用的测点数量 |
......@@ -228,7 +218,7 @@ TDengine 内置了一个名为 `INFORMATION_SCHEMA` 的数据库，提供对数
| --- | :-------: | ------------ | ------------------------------------------------------ |
| 1 | vgroup_id | INT | vgroup id |
| 2 | db_name | BINARY(32) | 数据库名 |
| 3 | tables | INT | 此 vgroup 内有多少表 |
| 3 | tables | INT | 此 vgroup 内有多少表。需要注意，`tables` 为 TDengine 关键字，作为列名使用时需要使用 ` 进行转义。 |
| 4 | status | BINARY(10) | 此 vgroup 的状态 |
| 5 | v1_dnode | INT | 第一个成员所在的 dnode 的 id |
| 6 | v1_status | BINARY(10) | 第一个成员的状态 |
......@@ -247,7 +237,7 @@ TDengine 内置了一个名为 `INFORMATION_SCHEMA` 的数据库，提供对数
| # | **列名** | **数据类型** | **说明** |
| --- | :------: | ------------ | ------------ |
| 1 | name | BINARY(32) | 配置项名称 |
| 2 | value | BINARY(64) | 该配置项的值 |
| 2 | value | BINARY(64) | 该配置项的值。需要注意，`value` 为 TDengine 关键字，作为列名使用时需要使用 ` 进行转义。 |
## INS_DNODE_VARIABLES
......@@ -257,7 +247,7 @@ TDengine 内置了一个名为 `INFORMATION_SCHEMA` 的数据库，提供对数
| --- | :------: | ------------ | ------------ |
| 1 | dnode_id | INT | dnode 的 ID |
| 2 | name | BINARY(32) | 配置项名称 |
| 3 | value | BINARY(64) | 该配置项的值 |
| 3 | value | BINARY(64) | 该配置项的值。需要注意，`value` 为 TDengine 关键字，作为列名使用时需要使用 ` 进行转义。 |
## INS_TOPICS
......@@ -288,5 +278,5 @@ TDengine 内置了一个名为 `INFORMATION_SCHEMA` 的数据库，提供对数
| 5 | source_db | BINARY(64) | 源数据库 |
| 6 | target_db | BIANRY(64) | 目的数据库 |
| 7 | target_table | BINARY(192) | 流计算写入的目标表 |
| 8 | watermark | BIGINT | watermark，详见 SQL 手册流式计算 |
| 9 | trigger | INT | 计算结果推送模式，详见 SQL 手册流式计算 |
| 8 | watermark | BIGINT | watermark，详见 SQL 手册流式计算。需要注意，`watermark` 为 TDengine 关键字，作为列名使用时需要使用 ` 进行转义。 |
| 9 | trigger | INT | 计算结果推送模式，详见 SQL 手册流式计算。需要注意，`trigger` 为 TDengine 关键字，作为列名使用时需要使用 ` 进行转义。 |
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