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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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how to resolve the problem that TDengine database has no function that converts the date format

how to resolve the problem that TDengine database has no function that converts the date format? I want to know the my data belong to which year, month, and day. but not a specific timestamp
Yu Chen
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No valid function in window query when using time window in TDengine

I'm trying to create a stream in TDengine. The following statement is ok: Select count(*),first(_ts),last_row(_ts),_value,devicecode from yxzt partiton by devicecode state_window(_value); However, when I change the statement to the following sql,…
superman
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failed to limit the number of results when using group by in TDengine

I want to limit the result of a query in TDengine. My sql statement is as follows: SELECT last_row(*),tel_device_id FROM geo WHERE account_id_cp IN (...) GROUP BY tel_device_id LIMIT 2000 However, the result is more than 2000. I cannot tell how to…
superman
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Tdengine 3.x, parameter buffer and vnode settings are unreasonable, how to deal with them?

Can I use taosdump to back up the data, create a new database, and import the data into the new database? The expected parameters can be adjusted. If not, is there a suitable solution? Version 3.0.1.8 if you use taosdump to back up one copy and…
zeje
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fail to delete data from TDengine

I want to delete some data from a table. First, I executed the following sql: select count(1) from dclm_device.device_int where identifier = "water_level"; I can see "Query OK, 1 rows in database" However, when I tried to delete the data from this…
JamesLiu
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Data base not specified in TDengine database 2.6.0.24

The version is 2.6.0.24. An error message is displayed if the database name is not specified when the TDengine GUI tool is connected In the 2.6.0.6 I don't need to specify database name in SQL.
Yu Chen
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how to check if I created a stream successfully in TDengine

I created a stream with the following statement: create stream device_running_s trigger WINDOW_CLOSE watermark 60m into device_running as select tbname,wcs_sx_runing,_wstart,_wend,_wduration from point partition by tbname…
JamesLiu
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An error occurred while transferring data from TDengine 2.4 to TDengine 3.0 with taosdump

taosdump.3340632973591 is from TDengine 2.4. When I try to recover data in TDengine 3.0 ,I have a problem. Here's the code root@nofeel:~# taosdump -i taosdump.3340632973591 taosdump: symbol lookup error: taosdump: undefined symbol:…
MrZao
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Does TDengine support to modify the TTL afterwards?

I create a super table with the following statement: CREATE STABLE `gps` (`st` TIMESTAMP, `loc_type` INT, `access_address` VARCHAR(200), `t` TIMESTAMP, `lat` FLOAT, `lng` FLOAT, `alt` FLOAT, `dir` FLOAT, `spd` FLOAT, `acc` INT) TAGS (`dev_id`…
superman
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fail to inser data when using TDengine

I encountered an error when inserting data into TDengine. I can see the error report in its log. ERROR vgId:5, msg:0x7fea18137cb0 failed to put into vnode queue since Invalid Vgroup ID, type:submit qtype:3 contLen:455,…
JamesLiu
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What type of data can be considered as status in the status window

TDengine DOC Here are two questions. Whether "字符串" includes NCHAR or BINARY? If "字符串" includes NCHAR.Whether the variable with "1.1" string value is valid in status window? TDengine sql value_str value is "1.0". TDengine version is 2.6.0.32.
MrZao
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Does TDengine support Chinese character as column and tag name?

I want to create a super table for my business requirement in TDengine. We need to represent some column and tag names with Chinese character. I didn't find examples for it. Does anyone know that can we implement it?
superman
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Does TDengine support modify column type?

As far as I know, we can change the type of column in MySQL, like ALTER TABLE t1 MODIFY b INT NOT NULL; I'm using TDengine, and I have lots of data stored. Now I want to change the type of one column from tinyint to tinyint unsigned. I saw some…
JamesLiu
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why 3.0.1.8 TDengine database's query performance is far better 3.0.1.4

this SQL: select * from meters limit 1000000 >> /dev/null; 3.0.1.4 takes 14 seconds, while 3.0.1.8 takes 2.4 seconds, which is quite a big difference. May I know which part of the code we optimized?
Yu Chen
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How to display the entire row of sql statement in TDengine？

I want to view the table creation statement in TDengine, So I execute the following sql: SHOW CREATE DATABASE However, it didn't display the entire row. How do I need to adjust it?
superman
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