表结构

openGemini大约 10 分钟约 2965 字

本章主要包括如下内容

SHOW TAG KEYS (查看表中所有TAG字段)
SHOW TAG VALUES (查看表中所有TAG字段及其对应的值)
SHOW FIELD KEYS (查看表中全部Field字段及其数据类型)
SHOW SERIES (查看全部时间线)
SHOW SERIES CARDINALITY (查询时间线统计数量)
SHOW SHARDS (查看数据分片信息)
SHOW SHARD GROUPS(查看分片组信息)

SHOW TAG KEYS

查看表中所有TAG字段

语法

SHOW TAG KEYS [ON <database_name>] [FROM_clause] [WHERE <tag_key> <operator> ['<tag_value>' | <regular_expression>]] [LIMIT_clause] [OFFSET_clause]

如果查询中没有包含ON <database_name>，您必须在CLI中使用USE <database_name>指定数据库，或者在openGemini API请求中使用参数db指定数据库。

示例

运行带有ON子句的SHOW TAG KEYS查询

> SHOW TAG KEYS ON "NOAA_water_database"
name: average_temperature
+----------+
| tagKey   |
+----------+
| location |
+----------+
1 columns, 1 rows in set

name: h2o_feet
+----------+
| tagKey   |
+----------+
| location |
+----------+
1 columns, 1 rows in set

name: h2o_pH
+----------+
| tagKey   |
+----------+
| location |
+----------+
1 columns, 1 rows in set

name: h2o_quality
+----------+
| tagKey   |
+----------+
| location |
| randtag  |
+----------+
1 columns, 2 rows in set

name: h2o_temperature
+----------+
| tagKey   |
+----------+
| location |
+----------+
1 columns, 1 rows in set

该查询返回数据库NOAA_water_database中的所有表的tag key。

> curl -G "http://localhost:8086/query?pretty=true" --data-urlencode "q=SHOW TAG KEYS on NOAA_water_database"
{
	"results": [{
		"statement_id": 0,
		"series": [{
			"name": "average_temperature",
			"columns": ["tagKey"],
			"values": [
				["location"]
			]
		}, {
			"name": "h2o_feet",
			"columns": ["tagKey"],
			"values": [
				["location"]
			]
		}, {
			"name": "h2o_pH",
			"columns": ["tagKey"],
			"values": [
				["location"]
			]
		}, {
			"name": "h2o_quality",
			"columns": ["tagKey"],
			"values": [
				["location"],
				["randtag"]
			]
		}, {
			"name": "h2o_temperature",
			"columns": ["tagKey"],
			"values": [
				["location"]
			]
		}]
	}]
}

运行不带有ON子句的SHOW TAG KEYS查询

使用USE <database_name>指定数据库：

> use NOAA_water_database
Elapsed: 452ns
> SHOW TAG KEYS
name: average_temperature
+----------+
| tagKey   |
+----------+
| location |
+----------+
1 columns, 1 rows in set

name: h2o_feet
+----------+
| tagKey   |
+----------+
| location |
+----------+
1 columns, 1 rows in set

name: h2o_pH
+----------+
| tagKey   |
+----------+
| location |
+----------+
1 columns, 1 rows in set

name: h2o_quality
+----------+
| tagKey   |
+----------+
| location |
| randtag  |
+----------+
1 columns, 2 rows in set

name: h2o_temperature
+----------+
| tagKey   |
+----------+
| location |
+----------+
1 columns, 1 rows in set

使用参数db指定数据库

> curl -G "http://localhost:8086/query?db=NOAA_water_database&pretty=true" --data-urlencode "q=SHOW TAG KEYS"
{
	"results": [{
		"statement_id": 0,
		"series": [{
				"name": "average_temperature",
				"columns": [
					"tagKey"
				],
				"values": [
					[
						"location"
					]
				]
			},
			{
				"name": "h2o_feet",
				"columns": [
					"tagKey"
				],
				"values": [
					[
						"location"
					]
				]
			},
			{
				"name": "h2o_pH",
				"columns": [
					"tagKey"
				],
				"values": [
					[
						"location"
					]
				]
			},
			{
				"name": "h2o_quality",
				"columns": [
					"tagKey"
				],
				"values": [
					[
						"location"
					],
					[
						"randtag"
					]
				]
			},
			{
				"name": "h2o_temperature",
				"columns": [
					"tagKey"
				],
				"values": [
					[
						"location"
					]
				]
			}
		]
	}]
}

运行带有多个子句的SHOW TAG KEYS查询

> SHOW TAG KEYS ON "NOAA_water_database" FROM "h2o_quality" LIMIT 1 OFFSET 1
name: h2o_quality
+---------+
| tagKey  |
+---------+
| randtag |
+---------+
1 columns, 1 rows in set

该查询返回数据库NOAA_water_database中名为h2o_quality的measurement里的tag key。LIMIT子句将返回的tag key的个数限制为1，OFFSET子句将输出结果偏移一个。

查看TAG的统计数量

在某些场景下，仅需要了解TAG数量，不关心具体的TAG，可以使用SHOW TAG KEY CARDINALITY命令，使用方式如下：

SHOW TAG KEY CARDINALITY [ON <database_name>] [FROM_CLAUSE]

例如：

> SHOW TAG KEY CARDINALITY
name: average_temperature
+-------+
| count |
+-------+
| 1     |
+-------+
1 columns, 1 rows in set

name: h2o_feet
+-------+
| count |
+-------+
| 1     |
+-------+
1 columns, 1 rows in set

name: h2o_pH
+-------+
| count |
+-------+
| 1     |
+-------+
1 columns, 1 rows in set

name: h2o_quality
+-------+
| count |
+-------+
| 2     |
+-------+
1 columns, 1 rows in set

name: h2o_temperature
+-------+
| count |
+-------+
| 1     |
+-------+
1 columns, 1 rows in set

> SHOW TAG KEY CARDINALITY FROM h2o_temperature
name: h2o_temperature
+-------+
| count |
+-------+
| 1     |
+-------+
1 columns, 1 rows in set

运行带条件的SHOW TAG KEYS查询

> SHOW TAG KEYS FROM h2o_quality WHERE location=coyote_creek
name: h2o_quality
+----------+
| tagKey   |
+----------+
| location |
| randtag  |
+----------+
1 columns, 2 rows in set

> SHOW TAG KEYS FROM h2o_quality WHERE location=coyote_creek LIMIT 1
name: h2o_quality
+----------+
| tagKey   |
+----------+
| location |
+----------+
1 columns, 1 rows in set

SHOW TAG VALUES

返回数据库中指定tag key的tag value。

语法

SHOW TAG VALUES [ON <database_name>] [FROM_CLAUSE] WITH KEY [ [<operator> "<tag_key>" | <regular_expression>] | [IN ("<tag_key1>","<tag_key2")]] [WHERE <tag_key> <operator> ['<tag_value>' | <regular_expression>]] [LIMIT_CLAUSE] [OFFSET_CLAUSE]

ON <database_name>是可选的。如果查询中没有包含ON <database_name>，您必须在CLI中使用USE <database_name>指定数据库，或者在HTTP API请求中使用参数db指定数据库。

WITH子句是必须要有的，它支持指定一个tag key、一个正则表达式或多个tag key。

FROM子句、WHERE子句、LIMIT子句和OFFSET子句是可选的。WHERE子句支持tag比较；在SHOW TAG VALUES查询中，field比较是无效的。

WITH子句和WHERE子句中支持的操作符：

操作符	含义
`=`	等于
`<>`	不等于
`!=`	不等于
`=~`	匹配
`!~`	不匹配

请查阅DML章节获得关于FROM子句、LIMIT、OFFSET子句、和正则表达式的介绍。

示例

运行带有ON子句的SHOW TAG VALUES查询

> SHOW TAG VALUES ON "NOAA_water_database" WITH KEY = "randtag"

name: h2o_quality
key       value
---       -----
randtag   1
randtag   2
randtag   3

该查询返回数据库NOAA_water_database中的tag key randtag的所有tag value。SHOW TAG VALUES将查询结果按measurement的名字进行分组。

运行不带有ON子句的SHOW TAG KEYS查询

使用USE <database_name>指定数据库：

> USE NOAA_water_database
Using database NOAA_water_database

> SHOW TAG VALUES WITH KEY = "randtag"

name: h2o_quality
key       value
---       -----
randtag   1
randtag   2
randtag   3

使用参数db指定数据库

> curl -G "http://localhost:8086/query?db=NOAA_water_database&pretty=true" --data-urlencode 'q=SHOW TAG VALUES WITH KEY = "randtag"'
{
	"results": [{
		"statement_id": 0,
		"series": [{
			"name": "h2o_quality",
			"columns": [
				"key",
				"value"
			],
			"values": [
				[
					"randtag",
					"1"
				],
				[
					"randtag",
					"2"
				],
				[
					"randtag",
					"3"
				]
			]
		}]
	}]
}

运行带有多个子句的SHOW TAG VALUES查询

> SHOW TAG VALUES ON "NOAA_water_database" WITH KEY IN ("location","randtag") WHERE "randtag" =~ /./ LIMIT 3

name: h2o_quality
key        value
---        -----
location   coyote_creek
location   santa_monica
randtag	   1

该查询从数据库NOAA_water_database的所有measurement中返回location或randtag的tag value，并且返回的数据还需满足条件：randtag的tag value不为空。LIMIT子句将返回的tag value的个数限制为3。

SHOW FIELD KEYS

返回field key和field value的数据类型。

语法

SHOW FIELD KEYS [ON <database_name>] [FROM <measurement_name>]

ON <database_name>是可选的
FROM子句是可选的。请参考FROM子句的介绍。

如果查询中没有包含ON <database_name>，您必须在CLI中使用USE <database_name>指定数据库，或者在openGemini API请求中使用参数db指定数据库。

示例

运行带有ON子句的SHOW FIELD KEYS查询

> SHOW FIELD KEYS ON "NOAA_water_database"

name: average_temperature
fieldKey            fieldType
--------            ---------
degrees             float

name: h2o_feet
fieldKey            fieldType
--------            ---------
level description   string
water_level         float

name: h2o_pH
fieldKey            fieldType
--------            ---------
pH                  float

name: h2o_quality
fieldKey            fieldType
--------            ---------
index               float

name: h2o_temperature
fieldKey            fieldType
--------            ---------
degrees             float

该查询返回数据库NOAA_water_database中每个measurement的field key以及对应的field value的数据类型。

运行不带有ON子句的SHOW FIELD KEYS查询

使用USE <database_name>指定数据库：

> USE NOAA_water_database
Using database NOAA_water_database

> SHOW FIELD KEYS

name: average_temperature
fieldKey            fieldType
--------            ---------
degrees             float

name: h2o_feet
fieldKey            fieldType
--------            ---------
level description   string
water_level         float

name: h2o_pH
fieldKey            fieldType
--------            ---------
pH                  float

name: h2o_quality
fieldKey            fieldType
--------            ---------
index               float

name: h2o_temperature
fieldKey            fieldType
--------            ---------
degrees             float

使用参数db指定数据库

> curl -G "http://localhost:8086/query?db=NOAA_water_database&pretty=true" --data-urlencode 'q=SHOW FIELD KEYS'
{
	"results": [{
		"statement_id": 0,
		"series": [{
				"name": "average_temperature",
				"columns": [
					"fieldKey",
					"fieldType"
				],
				"values": [
					[
						"degrees",
						"float"
					]
				]
			},
			{
				"name": "h2o_feet",
				"columns": [
					"fieldKey",
					"fieldType"
				],
				"values": [
					[
						"level description",
						"string"
					],
					[
						"water_level",
						"float"
					]
				]
			},
			{
				"name": "h2o_pH",
				"columns": [
					"fieldKey",
					"fieldType"
				],
				"values": [
					[
						"pH",
						"float"
					]
				]
			},
			{
				"name": "h2o_quality",
				"columns": [
					"fieldKey",
					"fieldType"
				],
				"values": [
					[
						"index",
						"float"
					]
				]
			},
			{
				"name": "h2o_temperature",
				"columns": [
					"fieldKey",
					"fieldType"
				],
				"values": [
					[
						"degrees",
						"float"
					]
				]
			}
		]
	}]
}

运行带有FROM子句的SHOW FIELD KEYS查询

> SHOW FIELD KEYS ON "NOAA_water_database" FROM "h2o_feet"

name: h2o_feet
fieldKey            fieldType
--------            ---------
level description   string
water_level         float

该查询返回数据库NOAA_water_database中measurement h2o_feet里的fields key以及对应的field value的数据类型。

SHOW SERIES

返回指定数据库的时间线。

语法

SHOW SERIES [ON <database_name>] [FROM_CLAUSE] [WHERE <tag_key> <operator> [ '<tag_value>' | <regular_expression>]] [LIMIT_CLAUSE] [OFFSET_CLAUSE]

ON <database_name>是可选的。如果查询中没有包含ON <database_name>，您必须在CLI中使用USE <database_name>指定数据库，或者在openGemini API请求中使用参数db指定数据库。

WHERE子句支持tag比较；在SHOW SERIES查询中，field比较是无效的。

WHERE子句中支持的操作符：

操作符	含义
`=`	等于
`<>`	不等于
`!=`	不等于
`=~`	匹配
`!~`	不匹配

参考FROM子句、LIMIT、OFFSET子句、和正则表达式的介绍。

示例

运行带有ON子句的SHOW SERIES查询

>>> SHOW SERIES ON NOAA_water_database
+---------------------------------------------+
| key                                         |
+---------------------------------------------+
| average_temperature,location=coyote_creek   |
| average_temperature,location=santa_monica   |
| h2o_feet,location=coyote_creek              |
| h2o_feet,location=santa_monica              |
| h2o_pH,location=coyote_creek                |
| h2o_pH,location=santa_monica                |
| h2o_quality,location=coyote_creek,randtag=1 |
| h2o_quality,location=coyote_creek,randtag=2 |
| h2o_quality,location=coyote_creek,randtag=3 |
| h2o_quality,location=santa_monica,randtag=1 |
| h2o_quality,location=santa_monica,randtag=2 |
| h2o_quality,location=santa_monica,randtag=3 |
| h2o_temperature,location=coyote_creek       |
| h2o_temperature,location=santa_monica       |
+---------------------------------------------+
1 columns, 14 rows in set

该查询的输出类似行协议格式。第一个逗号之前的所有内容是measurement的名字。第一个逗号之后的所有内容都是tag key或者tag value。数据库NOAA_water_database有五个不同的measurement和14个不同的系列。

运行不带有ON子句的SHOW SERIES查询

使用USE <database_name>指定数据库：

> USE NOAA_water_database
Elapsed: 561ns
> SHOW SERIES
+---------------------------------------------+
| key                                         |
+---------------------------------------------+
| average_temperature,location=coyote_creek   |
| average_temperature,location=santa_monica   |
| h2o_feet,location=coyote_creek              |
| h2o_feet,location=santa_monica              |
| h2o_pH,location=coyote_creek                |
| h2o_pH,location=santa_monica                |
| h2o_quality,location=coyote_creek,randtag=1 |
| h2o_quality,location=coyote_creek,randtag=2 |
| h2o_quality,location=coyote_creek,randtag=3 |
| h2o_quality,location=santa_monica,randtag=1 |
| h2o_quality,location=santa_monica,randtag=2 |
| h2o_quality,location=santa_monica,randtag=3 |
| h2o_temperature,location=coyote_creek       |
| h2o_temperature,location=santa_monica       |
+---------------------------------------------+
1 columns, 14 rows in set

使用参数db指定数据库

> curl -G "http://localhost:8086/query?db=NOAA_water_database&pretty=true" --data-urlencode "q=SHOW SERIES"
{
	"results": [{
		"statement_id": 0,
		"series": [{
			"columns": [
				"key"
			],
			"values": [
				[
					"average_temperature,location=coyote_creek"
				],
				[
					"average_temperature,location=santa_monica"
				],
				[
					"h2o_feet,location=coyote_creek"
				],
				[
					"h2o_feet,location=santa_monica"
				],
				[
					"h2o_pH,location=coyote_creek"
				],
				[
					"h2o_pH,location=santa_monica"
				],
				[
					"h2o_quality,location=coyote_creek,randtag=1"
				],
				[
					"h2o_quality,location=coyote_creek,randtag=2"
				],
				[
					"h2o_quality,location=coyote_creek,randtag=3"
				],
				[
					"h2o_quality,location=santa_monica,randtag=1"
				],
				[
					"h2o_quality,location=santa_monica,randtag=2"
				],
				[
					"h2o_quality,location=santa_monica,randtag=3"
				],
				[
					"h2o_temperature,location=coyote_creek"
				],
				[
					"h2o_temperature,location=santa_monica"
				]
			]
		}]
	}]
}

运行带有多个子句的SHOW SERIES查询

> SHOW SERIES ON NOAA_water_database FROM "h2o_quality" WHERE "location" = 'coyote_creek' LIMIT 2
+---------------------------------------------+
| key                                         |
+---------------------------------------------+
| h2o_quality,location=coyote_creek,randtag=1 |
| h2o_quality,location=coyote_creek,randtag=2 |
+---------------------------------------------+
1 columns, 2 rows in set

该查询返回数据库NOAA_water_database中，与measurement h2o_quality和tag location = coyote_creek相关联的所有系列。LIMIT子句将返回的系列个数限制为2。

警告

SHOW SERIES返回表中所有时间线，对内存资源占用较大，慎用！

如需使用，一定要使用条件过滤

SHOW SERIES CARDINALITY

返回指定数据库的时间线数量，结果按时间分组

SHOW SERIES CARDINALITY [ON <database_name>] [FROM_clause]

示例

> SHOW SERIES CARDINALITY ON NOAA_water_database
+----------------------+----------------------+-------+
| startTime            | endTime              | count |
+----------------------+----------------------+-------+
| 2019-08-12T00:00:00Z | 2019-08-19T00:00:00Z | 14    |
+----------------------+----------------------+-------+
3 columns, 1 rows in set

+----------------------+----------------------+-------+
| startTime            | endTime              | count |
+----------------------+----------------------+-------+
| 2019-08-19T00:00:00Z | 2019-08-26T00:00:00Z | 14    |
+----------------------+----------------------+-------+
3 columns, 1 rows in set

+----------------------+----------------------+-------+
| startTime            | endTime              | count |
+----------------------+----------------------+-------+
| 2019-08-26T00:00:00Z | 2019-09-02T00:00:00Z | 14    |
+----------------------+----------------------+-------+
3 columns, 1 rows in set

+----------------------+----------------------+-------+
| startTime            | endTime              | count |
+----------------------+----------------------+-------+
| 2019-09-02T00:00:00Z | 2019-09-09T00:00:00Z | 14    |
+----------------------+----------------------+-------+
3 columns, 1 rows in set

+----------------------+----------------------+-------+
| startTime            | endTime              | count |
+----------------------+----------------------+-------+
| 2019-09-09T00:00:00Z | 2019-09-16T00:00:00Z | 14    |
+----------------------+----------------------+-------+
3 columns, 1 rows in set

+----------------------+----------------------+-------+
| startTime            | endTime              | count |
+----------------------+----------------------+-------+
| 2019-09-16T00:00:00Z | 2019-09-23T00:00:00Z | 14    |
+----------------------+----------------------+-------+
3 columns, 1 rows in set

> SHOW SERIES CARDINALITY ON NOAA_water_database FROM h2o_quality
+----------------------+----------------------+-------+
| startTime            | endTime              | count |
+----------------------+----------------------+-------+
| 2019-08-12T00:00:00Z | 2019-08-19T00:00:00Z | 6     |
+----------------------+----------------------+-------+
3 columns, 1 rows in set

+----------------------+----------------------+-------+
| startTime            | endTime              | count |
+----------------------+----------------------+-------+
| 2019-08-19T00:00:00Z | 2019-08-26T00:00:00Z | 6     |
+----------------------+----------------------+-------+
3 columns, 1 rows in set

+----------------------+----------------------+-------+
| startTime            | endTime              | count |
+----------------------+----------------------+-------+
| 2019-08-26T00:00:00Z | 2019-09-02T00:00:00Z | 6     |
+----------------------+----------------------+-------+
3 columns, 1 rows in set

+----------------------+----------------------+-------+
| startTime            | endTime              | count |
+----------------------+----------------------+-------+
| 2019-09-02T00:00:00Z | 2019-09-09T00:00:00Z | 6     |
+----------------------+----------------------+-------+
3 columns, 1 rows in set

+----------------------+----------------------+-------+
| startTime            | endTime              | count |
+----------------------+----------------------+-------+
| 2019-09-09T00:00:00Z | 2019-09-16T00:00:00Z | 6     |
+----------------------+----------------------+-------+
3 columns, 1 rows in set

+----------------------+----------------------+-------+
| startTime            | endTime              | count |
+----------------------+----------------------+-------+
| 2019-09-16T00:00:00Z | 2019-09-23T00:00:00Z | 6     |
+----------------------+----------------------+-------+
3 columns, 1 rows in set

SHOW SHARDS

返回指定数据库的分片信息

示例

> SHOW SHARDS
name: NOAA_water_database
+----+---------------------+------------------+-------------+----------------------+----------------------+----------------------+--------+------+------------------+
| id | database            | retention_policy | shard_group | start_time           | end_time             | expiry_time          | owners | tier | downSample_level |
+----+---------------------+------------------+-------------+----------------------+----------------------+----------------------+--------+------+------------------+
| 19 | NOAA_water_database | autogen          | 19          | 2019-08-12T00:00:00Z | 2019-08-19T00:00:00Z | 2019-08-19T00:00:00Z | 2      | warm | 0                |
| 20 | NOAA_water_database | autogen          | 20          | 2019-08-19T00:00:00Z | 2019-08-26T00:00:00Z | 2019-08-26T00:00:00Z | 2      | warm | 0                |
| 21 | NOAA_water_database | autogen          | 21          | 2019-08-26T00:00:00Z | 2019-09-02T00:00:00Z | 2019-09-02T00:00:00Z | 2      | warm | 0                |
| 18 | NOAA_water_database | autogen          | 18          | 2019-09-02T00:00:00Z | 2019-09-09T00:00:00Z | 2019-09-09T00:00:00Z | 2      | warm | 0                |
| 22 | NOAA_water_database | autogen          | 22          | 2019-09-09T00:00:00Z | 2019-09-16T00:00:00Z | 2019-09-16T00:00:00Z | 2      | warm | 0                |
| 23 | NOAA_water_database | autogen          | 23          | 2019-09-16T00:00:00Z | 2019-09-23T00:00:00Z | 2019-09-23T00:00:00Z | 2      | warm | 0                |
+----+---------------------+------------------+-------------+----------------------+----------------------+----------------------+--------+------+------------------+
10 columns, 6 rows in set

每一条数据表示一个数据库的分片信息，每个分片包含所使用的数据保留策略、分片起始时间等。相关阅读数据保留策略

SHOW SHARD GROUPS

返回指定数据库的分片组信息

示例

> SHOW SHARD GROUPS
name: shard groups
+----+---------------------+------------------+----------------------+----------------------+----------------------+
| id | database            | retention_policy | start_time           | end_time             | expiry_time          |
+----+---------------------+------------------+----------------------+----------------------+----------------------+
| 19 | NOAA_water_database | autogen          | 2019-08-12T00:00:00Z | 2019-08-19T00:00:00Z | 2019-08-19T00:00:00Z |
| 20 | NOAA_water_database | autogen          | 2019-08-19T00:00:00Z | 2019-08-26T00:00:00Z | 2019-08-26T00:00:00Z |
| 21 | NOAA_water_database | autogen          | 2019-08-26T00:00:00Z | 2019-09-02T00:00:00Z | 2019-09-02T00:00:00Z |
| 18 | NOAA_water_database | autogen          | 2019-09-02T00:00:00Z | 2019-09-09T00:00:00Z | 2019-09-09T00:00:00Z |
| 22 | NOAA_water_database | autogen          | 2019-09-09T00:00:00Z | 2019-09-16T00:00:00Z | 2019-09-16T00:00:00Z |
| 23 | NOAA_water_database | autogen          | 2019-09-16T00:00:00Z | 2019-09-23T00:00:00Z | 2019-09-23T00:00:00Z |
+----+---------------------+------------------+----------------------+----------------------+----------------------+
6 columns, 6 rows in set

这里有6个分片组，结合SHOW SHARDS命令可以看出，每个分片组包含一个分片(SHARD)。openGemini单机默认初始化一个分片(SHARD)，如果是三节点的集群，则初始化为三个分片（每个节点一个）。当一个SHARD GROUP到期后，系统会创建新的SHARD GROUP，并分配新的分片 (SHARD)。相关阅读SHARD GROUP DURATION

表结构

# SHOW TAG KEYS

# 语法

# 示例

# SHOW TAG VALUES

# 语法

# 示例

# SHOW FIELD KEYS

# 语法

# 示例

# SHOW SERIES

# 语法

# 示例

# SHOW SERIES CARDINALITY

# 示例

# SHOW SHARDS

# 示例

# SHOW SHARD GROUPS

# 示例

SHOW TAG KEYS

语法

示例

SHOW TAG VALUES

语法

示例

SHOW FIELD KEYS

语法

示例

SHOW SERIES

语法

示例

SHOW SERIES CARDINALITY

示例

SHOW SHARDS

示例

SHOW SHARD GROUPS

示例