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Questions tagged [tdengine]

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.

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what is the difference between TDengine 3.0 datafile and 2.0 datafile?

in the 2.0, I can see the datafile composed of three files which are .data file,.last,.head file. By the time of 3.0 version. it is changed to data, stt, head, sma file. what is the difference between TDengine 3.0 datafile and 2.0 datafile?
Yu Chen
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TDengine steam computing does not support write data to the table that already has data

When I use TDengine database streaming computing, I found a problem,that is when I want to change my rule ,it is not supported, or I create a new stream computing write to this table, it is not supported either. How should I handle the above…
Yu Chen
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what is the main difference between data subscription and streaming computing in TDengine database?

what is the main difference between data subscription and streaming computing in TDengine database? As I check ,they all push the data to the consumer in real time I didn't tell the difference
Yu Chen
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what is the .stt file used for in TDengine database?

what is the .stt file used for in TDengine database ? under the dataDir some of the file is called .stt like this : ssn@TDengine:/var/lib/taos/vnode/vnode14$ cd .. ssn@TDengine:/var/lib/taos/vnode$ ls -ltR | grep -i stt -rwxrwxrwx 1 root root …
Yu Chen
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as a time-series database ,what is the main difference between TDengine and ClickHouse

our company is seeking for the time-series data resolution , I don't understand the specific advantages between TDengine and ClickHouse. does anyone have the performance benchmark ? hope to get a specific comparison between these two database , I…
Yu Chen
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Weird query result when the fill clause is existed

When using the TDengine (v3.0.2), I found that the query result is some how weird when the fill clause exists in the time window query. And the following SQL statements can produce the result. create table tu (ts timestamp, k int, z…
Roony
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An error occurred while query data from TDengine-client-3.0.2.0-Windows-x64

My SQL: select * from meters order by ts; Here's the retult from TDengine-server-3.0.2.0-Linux-x64 ts tv cs th report_time device_no 2022-12-02 09:22:22.249 30 1 50 2022-12-02 09:22:22.249 d001 2022-12-02 09:59:54.664 27 2 20 2022-12-02…
moxuan
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time range error when using interval in TDengine

I have an sql statement: select _WSTART startTime, _WEND endTime, avg(drp) drp, avg(intv) intv, avg(pdr) pdr, avg(dyp) dyp, avg(dy) dy from st_pptn where tm >= 1653619243000 interval(1h) fill(VALUE, 0) It reported an error when…
superman
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Unable to establish connection While execute transaction in TDengine

It reported an error when I wanted to create an new database in TDengine. create database pows; The error was: DB error: Unable to establish connection While execute transaction Then I executed 'show transactions\G;` to show the transaction…
JamesLiu
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Get the timestamp of max value in TDengine

I'm trying to downsample with interval in TDengine. I have a statement: select _wstart, max(val) max_val, min(val) min_val from d1001 interval(5s); enter image description here You can see in the picture, and it is ok. Now I want to get the…
superman
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Not a single-group group function in TDengine

I'm writing a sql with partition by in TDengine database. My statement is: select app_id, task_name, sum(allocated) as allocated from ( select tbname as app_id, task_name, apercentile(allocated, 90) as allocated from…
superman
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Invalid timeline function when using derivative function in TDengine

I'm executing a derivative function in TDengine database, and it reports an error. My sql statement is: select derivative(errors, 1s, 1) as errors from (select sum(errors) as errors from log.dnodes_info where ts>="2022-12-06 14:08:42" and ts <…
JamesLiu
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Cann't find the table when execting query in TDengine

I have a series of tables in TDengine database. If I execute "show tables", I can see all of them. However, when I execute some queries on a table, it reports "Fail to get table info". You can see the error information on the picture. enter image…
JamesLiu
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“no taos in java lib path” when using TDengine on MacOS

Does anyone use TDengine database on MacOS? I installed Java and TDengine, and configure the path. However, it still reports the following error: no taos in java lib path Do I miss some steps?
superman
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No such file or directory when creating UDF in TDengine

I created a scalar User-Defined-Function according the document of TDengine. CREATE FUNCTION bit_and AS "/usr/lib/libbitand.so" OUTPUTTYPE INT; It reported an error: No such file or directory I checked the path, and it is correct. I don't know…
JamesLiu
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