- All the data in `tag_set` will be converted to nchar type automatically .
- Each data in `field_set` must be self-descriptive for its data type. For example 1.2f32 means a value 1.2 of float type. Without the "f" type suffix, it will be treated as type double.
- Multiple kinds of precision can be used for the `timestamp` field. Time precision can be from nanosecond (ns) to hour (h).
- You can configure smlChildTableName in taos.cfg to specify table names, for example, `smlChildTableName=tname`. You can insert `st,tname=cpul,t1=4 c1=3 1626006833639000000` and the cpu1 table will be automatically created. Note that if multiple rows have the same tname but different tag_set values, the tag_set of the first row is used to create the table and the others are ignored.
- It is assumed that the order of field_set in a supertable is consistent, meaning that the first record contains all fields and subsequent records store fields in the same order. If the order is not consistent, set smlDataFormat in taos.cfg to false. Otherwise, data will be written out of order and a database error will occur.(smlDataFormat in taos.cfg default to false after version of 3.0.1.3)
:::
For more details please refer to [InfluxDB Line Protocol](https://docs.influxdata.com/influxdb/v2.0/reference/syntax/line-protocol/) and [TDengine Schemaless](/reference/schemaless/#Schemaless-Line-Protocol)
...
...
@@ -64,3 +65,7 @@ For more details please refer to [InfluxDB Line Protocol](https://docs.influxdat
<CLine />
</TabItem>
</Tabs>
## Query Examples
If you want query the data of `location=California.LosAngeles,groupid=2`，here is the query sql：
select * from `meters.voltage` where location="California.LosAngeles" and groupid=2
- The defult child table name is generated by rules.You can configure smlChildTableName in taos.cfg to specify chile table names, for example, `smlChildTableName=tname`. You can insert `meters.current 1648432611250 11.3 tname=cpu1 location=California.LosAngeles groupid=3` and the cpu1 table will be automatically created. Note that if multiple rows have the same tname but different tag_set values, the tag_set of the first row is used to create the table and the others are ignored.
Please refer to [OpenTSDB Telnet API](http://opentsdb.net/docs/build/html/api_telnet/put.html) for more details.
## Examples
...
...
@@ -79,3 +79,6 @@ taos> select tbname, * from `meters.current`;
@@ -48,7 +48,7 @@ Please refer to [OpenTSDB HTTP API](http://opentsdb.net/docs/build/html/api_http
- In JSON protocol, strings will be converted to nchar type and numeric values will be converted to double type.
- Only data in array format is accepted and so an array must be used even if there is only one row.
- The defult child table name is generated by rules.You can configure smlChildTableName in taos.cfg to specify chile table names, for example, `smlChildTableName=tname`. You can insert `"tags": { "host": "web02","dc": "lga","tname":"cpu1"}` and the cpu1 table will be automatically created. Note that if multiple rows have the same tname but different tag_set values, the tag_set of the first row is used to create the table and the others are ignored.
:::
## Examples
...
...
@@ -94,3 +94,6 @@ taos> select * from `meters.current`;
@@ -181,6 +181,14 @@ In TDengine, the first column of all tables must be a timestamp. This column is
select_rowts,max(current)frommeters;
```
**\_IROWTS**
The \_IROWTS pseudocolumn can only be used with INTERP function. This pseudocolumn can be used to retrieve the corresponding timestamp column associated with the interpolation results.
- The number of rows in the result set of `INTERP` is determined by the parameter `EVERY`. Starting from timestamp1, one interpolation is performed for every time interval specified `EVERY` parameter.
- Interpolation is performed based on `FILL` parameter.
- `INTERP` can only be used to interpolate in single timeline. So it must be used with `partition by tbname` when it's used on a STable.
- Pseudo column `_irowts` can be used along with `INTERP` to return the timestamps associated with interpolation points(support after version 3.0.1.4).
@@ -11,7 +11,15 @@ TDengine includes a built-in database named `INFORMATION_SCHEMA` to provide acce
4. Future versions of TDengine can add new columns to INFORMATION_SCHEMA tables without affecting existing business systems.
5. It is easier for users coming from other database management systems. For example, Oracle users can query data dictionary tables.
Note: SHOW statements are still supported for the convenience of existing users.
:::info
- SHOW statements are still supported for the convenience of existing users.
- Some columns in the system table may be keywords, and you need to use the escape character '\`' when querying, for example, to query the VGROUPS in the database `test`:
```sql
select`vgroups`fromins_databaseswherename='test';
```
:::
This document introduces the tables of INFORMATION_SCHEMA and their structure.
...
...
@@ -102,7 +110,11 @@ Provides information about user-created databases. Similar to SHOW DATABASES.
| 24 | wal_retention_period | INT | WAL retention period |
| 25 | wal_retention_size | INT | Maximum WAL size |
| 26 | wal_roll_period | INT | WAL rotation period |
| 3 | _ROWTS pseudocolumn | Added | Indicates the primary key. Alias of _C0.
| 4 | INFORMATION_SCHEMA | Added | Database for system metadata containing all schema definitions
| 5 | PERFORMANCE_SCHEMA | Added | Database for system performance information.
| 6 | Connection queries | Deprecated | Connection queries are no longer supported. The syntax and interfaces are deprecated.
| 7 | Mixed operations | Enhanced | Mixing scalar and vector operations in queries has been enhanced and is supported in all SELECT clauses.
| 8 | Tag operations | Added | Tag columns can be used in queries and clauses like data columns.
| 9 | Timeline clauses and time functions in supertables | Enhanced | When PARTITION BY is not used, data in supertables is merged into a single timeline.
| 4 | _IROWTS pseudocolumn | Added | Used to retrieve timestamps with INTERP function.
| 5 | INFORMATION_SCHEMA | Added | Database for system metadata containing all schema definitions
| 6 | PERFORMANCE_SCHEMA | Added | Database for system performance information.
| 7 | Connection queries | Deprecated | Connection queries are no longer supported. The syntax and interfaces are deprecated.
| 8 | Mixed operations | Enhanced | Mixing scalar and vector operations in queries has been enhanced and is supported in all SELECT clauses.
| 9 | Tag operations | Added | Tag columns can be used in queries and clauses like data columns.
| 10 | Timeline clauses and time functions in supertables | Enhanced | When PARTITION BY is not used, data in supertables is merged into a single timeline.
_taosSql_implementsGo's `database/sql/driver` interface via cgo. You can use the [`database/sql`](https://golang.org/pkg/database/sql/) interface by simply introducing the driver.
For native connection, you need to verify that both the client driver and the Python connector itself are installed correctly. The client driver and Python connector have been installed properly if you can successfully import the `taos` module. In the Python Interactive Shell, you can type.
...
...
@@ -118,7 +118,7 @@ Requirement already satisfied: taospy in c:\users\username\appdata\local\program
Before establishing a connection with the connector, we recommend testing the connectivity of the local TDengine CLI to the TDengine cluster.
Ensure that the TDengine instance is up and that the FQDN of the machines in the cluster (the FQDN defaults to hostname if you are starting a standalone version) can be resolved locally, by testing with the `ping` command.
...
...
@@ -173,7 +173,7 @@ If the test is successful, it will output the server version information, e.g.
The following example code assumes that TDengine is installed locally and that the default configuration is used for both FQDN and serverPort.
@@ -47,9 +47,8 @@ In the schemaless writing data line protocol, each data item in the field_set ne
-`t`, `T`, `true`, `True`, `TRUE`, `f`, `F`, `false`, and `False` will be handled directly as BOOL types.
For example, the following data rows indicate that the t1 label is "3" (NCHAR), the t2 label is "4" (NCHAR), and the t3 label
is "t3" to the super table named `st` labeled "t3" (NCHAR), write c1 column as 3 (BIGINT), c2 column as false (BOOL), c3 column
is "passit" (BINARY), c4 column is 4 (DOUBLE), and the primary key timestamp is 1626006833639000000 in one row.
For example, the following data rows write c1 column as 3 (BIGINT), c2 column as false (BOOL), c3 column
as "passit" (BINARY), c4 column as 4 (DOUBLE), and the primary key timestamp as 1626006833639000000 to child table with the t1 label as "3" (NCHAR), the t2 label as "4" (NCHAR), and the t3 label as "t3" (NCHAR) and the super table named `st`.
@@ -69,7 +68,7 @@ Schemaless writes process row data according to the following principles.
Note that tag_key1, tag_key2 are not the original order of the tags entered by the user but the result of using the tag names in ascending order of the strings. Therefore, tag_key1 is not the first tag entered in the line protocol.
The string's MD5 hash value "md5_val" is calculated after the ranking is completed. The calculation result is then combined with the string to generate the table name: "t_md5_val". "t_" is a fixed prefix that every table generated by this mapping relationship has.
You can configure smlChildTableName to specify table names, for example, `smlChildTableName=tname`. You can insert `st,tname=cpul,t1=4 c1=3 1626006833639000000` and the cpu1 table will be automatically created. Note that if multiple rows have the same tname but different tag_set values, the tag_set of the first row is used to create the table and the others are ignored.
You can configure smlChildTableName in taos.cfg to specify table names, for example, `smlChildTableName=tname`. You can insert `st,tname=cpul,t1=4 c1=3 1626006833639000000` and the cpu1 table will be automatically created. Note that if multiple rows have the same tname but different tag_set values, the tag_set of the first row is used to create the table and the others are ignored.
2. If the super table obtained by parsing the line protocol does not exist, this super table is created.
3. If the subtable obtained by the parse line protocol does not exist, Schemaless creates the sub-table according to the subtable name determined in steps 1 or 2.
...
...
@@ -78,7 +77,7 @@ You can configure smlChildTableName to specify table names, for example, `smlChi
NULL.
6. For BINARY or NCHAR columns, if the length of the value provided in a data row exceeds the column type limit, the maximum length of characters allowed to be stored in the column is automatically increased (only incremented and not decremented) to ensure complete preservation of the data.
7. Errors encountered throughout the processing will interrupt the writing process and return an error code.
8. It is assumed that the order of field_set in a supertable is consistent, meaning that the first record contains all fields and subsequent records store fields in the same order. If the order is not consistent, set smlDataFormat to false. Otherwise, data will be written out of order and a database error will occur.
8. It is assumed that the order of field_set in a supertable is consistent, meaning that the first record contains all fields and subsequent records store fields in the same order. If the order is not consistent, set smlDataFormat in taos.cfg to false. Otherwise, data will be written out of order and a database error will occur.(smlDataFormat in taos.cfg default to false after version of 3.0.1.3)
:::tip
All processing logic of schemaless will still follow TDengine's underlying restrictions on data structures, such as the total length of each row of data cannot exceed
@@ -15,6 +15,7 @@ To write Telegraf data to TDengine requires the following preparations.
- The TDengine cluster is deployed and functioning properly
- taosAdapter is installed and running properly. Please refer to the [taosAdapter manual](/reference/taosadapter) for details.
- Telegraf has been installed. Please refer to the [official documentation](https://docs.influxdata.com/telegraf/v1.22/install/) for Telegraf installation.
- Telegraf collects the running status measurements of current system. You can enable [input plugins](https://docs.influxdata.com/telegraf/v1.22/plugins/) to insert [other formats](https://docs.influxdata.com/telegraf/v1.24/data_formats/input/) data to Telegraf then forward to TDengine.
## Configuration steps
<Telegraf/>
...
...
@@ -31,11 +32,12 @@ Use TDengine CLI to verify Telegraf correctly writing data to TDengine and read
```
taos> show databases;
name | created_time | ntables | vgroups | replica | quorum | days | keep | cache(MB) | blocks | minrows | maxrows | wallevel | fsync | comp | cachelast | precision | update | status |
- TDengine take influxdb format data and create unique ID for table names by the rule.
The user can configure `smlChildTableName` parameter to generate specified table names if he/she needs. And he/she also need to insert data with specified data format.
For example, Add `smlChildTableName=tname` in the taos.cfg file. Insert data `st,tname=cpu1,t1=4 c1=3 1626006833639000000` then the table name will be cpu1. If there are multiple lines has same tname but different tag_set, the first line's tag_set will be used to automatically creating table and ignore other lines. Please refer to [TDengine Schemaless](/reference/schemaless/#Schemaless-Line-Protocol)
It's a Lua implementation for [TDengine](https://github.com/taosdata/TDengine), an open-sourced big data platform designed and optimized for the Internet of Things (IoT), Connected Cars, Industrial IoT, and IT Infrastructure and Application Monitoring. You may need to install Lua5.3 .
As TDengine is built with lua-enable with default configure, the built-in lua lib conflicts with external lua lib. The following commands require TDengine built with lua-disable.
echo-e"${GREEN_DARK}To access ${productName}${NC}: use ${GREEN_UNDERLINE}${clientName} -h $serverFqdn${NC} in shell OR from ${GREEN_UNDERLINE}http://127.0.0.1:${nginx_port}${NC}"
echo-e"${GREEN_DARK}To access ${productName}${NC}: use ${GREEN_UNDERLINE}${clientName} -h $serverFqdn${NC} in shell OR from ${GREEN_UNDERLINE}http://127.0.0.1:${web_port}${NC}"
else
echo-e"${GREEN_DARK}To access ${productName}${NC}: use ${GREEN_UNDERLINE}${clientName} -h $serverFqdn${NC} in shell${NC}"
fi
...
...
@@ -906,6 +859,7 @@ function installProduct() {
install_connector
fi
install_examples
install_web
if[-z$1];then# install service and client
# For installing new
...
...
@@ -915,17 +869,6 @@ function installProduct() {
install_adapter_config
openresty_work=false
if["$verMode"=="cluster"];then
# Check if nginx is installed successfully
if type curl &>/dev/null;then
if curl -sSf http://127.0.0.1:${nginx_port} &>/dev/null;then
echo-e"\033[44;32;1mNginx for ${productName} is installed successfully!${NC}"
openresty_work=true
else
echo-e"\033[44;31;5mNginx for ${productName} does not work! Please try again!\033[0m"
