TDengine is an open-sourced big data platform under GNU AGPL v3.0, designed and optimized for the Internet of Things (IoT), Connected Cars, Industrial IoT, and IT Infrastructure and Application Monitoring.
Questions tagged [tdengine]
345 questions
0
votes
2 answers
anybody knows how to show a complete line in taos shell in TDengine?
the query results showed in taos shell are truncated, anybody knows how to disable this truncate? I have tried to use \G, but the output format is different.
taos> select * from tb1;
ts | f1 | f2 …
stackover1024
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0
votes
1 answer
use taosBenchmark to insert binary data with specified length in command line
In TDengine database, I tried to use taosBenchmark to write binary data with specified length in command line, but I got following error
root@Alex ~ $ taosBenchmark -b int,int,binary(100)
-bash: syntax error near unexpected token `('
what is the…
Alex
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- 6
0
votes
1 answer
why TDengine database returns null when the count function has no record
why TDengine database returns null when the count function has no record
it made me confused why designer do this? any good?
Yu Chen
- 70
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0
votes
3 answers
Is TDengine SQL support do caculate between columns and tag?
I was using TDengine for some times,and I tried to caculate some rate through the tags and columns. The follow is my table structure:
create table p(ts timestamp,voltag int)tags(nominal_voltage int);
Any calculate SQL is
select…
xiaolei
- 43
- 1
- 6
0
votes
1 answer
Using C# TDengine driver to consume data failed
I used C# TDengine driver to subscribe data from taos database. My a sample code is like bellow:
public void RunSubscribeWithoutCallback(IntPtr conn, string table)
{
PrepareData(conn, table);
string topic =…
Ray Shown
- 33
- 6
0
votes
1 answer
something wrong when writing influx data into TDengine
I am trying to port my application which writing InfluxDb data to TDengine via its schemaless interface. I think it should be very easy but actually not.
Java code is below:
public void batchInsert() {
JSONObject json = new…
hook capt
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- 5
0
votes
2 answers
how to order records in stable query in TDengine?
I created a stable and a few sub-tables, then I used below SQL to list all records, but the result is not ordered by ts column. any way to do it?
select * from stable1
stackover1024
- 26
- 1
0
votes
1 answer
What can know that my stream table is done while using tdengine’s continuous query?
I followed TDengine’s website about continuous query. And I used the follow command to create a table to store the continuous query result.
create table if not exists tmp as select count(*) from test interval(1m) sliding (30s);
After execute upper…
Ray Shown
- 33
- 6
0
votes
1 answer
schemaless insert in TDengine using jdbc connector
I tried to do a schemaless insert by using TDengine JDBC connector, but got following error
java.sql.SQLException: TDengine ERROR (2350): failed to insertLines
at com.taosdata.jdbc.TSDBError.createSQLException(TSDBError.java:76)
at…
Alex
- 109
- 6
0
votes
1 answer
What is the max longest database name in tdengine?
Just like the title, I tried to create a database in tdengine, but I meet a DB error throw by Taos shell. Which said that “invalid operation:name too long”.
Does anyone know the max length of database allowed in tdengine? Is this is configurable?
Ray Shown
- 33
- 6
0
votes
1 answer
how many options do we have for data compression in TDengine database?
In TDengine database, there is a data compression configuration in /etc/taos/taos.cfg
# enable/disable compression
# comp 2
the default option is 2, so how many options do we have for comp, what is the difference for each option?
Alex
- 109
- 6
0
votes
1 answer
Tdengine syntax order issue
TDengine sql error when executing aggregate query:
select avg(value) as gauge from table1 where ts >= now - 30d and ts <= now group by cluster interval(30d)
DB error: syntax error near "interval(30d);" (0.000552s)
What are the syntax errors in…
naissance
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- 12
0
votes
1 answer
JDBC restful SQL request for TDengine
My springboot project has correctly configured JDBC of TDengine:
datasource:
dynamic:
druid:
max-active: 20
initial-size: 4
min-idle: 4
max-wait: 60000
time-between-eviction-runs-millis: 60000
…
naissance
- 36
- 12
0
votes
2 answers
TDengine SQL issue
I recently found the select syntax in TDengine SQL is slightly different from mysql due to stable. But I cannot give a reasonable explanation. Let me show the emample:
Here is the stable structure:
describe mystable;
Field …
naissance
- 36
- 12
0
votes
1 answer
what "balance" used for in TDengine database
there is a configuration parameter "balance" in /etc/taos/taos.cfg, the default value is 1, I am wondering what is it and how to use it?
# enable/disable load balancing
# balance 1
Alex
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