Bug: TDEngine Version 3.3.4.8 - range fill(prev) Yields Output with Invalid Characters

[mesquita]

Bug Description

We are having an issue when querying the database using range combined with fill(prev) where the end range timestamp extends beyond the last occurrence of a tag sample.

When trying to make a query like this:

select _irowts as `time`,
    `tag`,
    interp(`value`) as `value`
from sensors
where `tag` in ('ABC.PV')
partition by tbname
range('2024-12-01 00:00:00', '2025-01-01 00:00:00') every(600s) fill(prev);

the current output in this version has for the output tag the following value:

ABC.��

Instead of returning the expected value ABC.PV, the tag field contains invalid characters such as \x00\x00 when the query includes a “future” value (i.e., a timestamp after the last sample for the tag).

To Reproduce

1. Run a query similar to the example above.
2. Ensure the range includes an end timestamp beyond the last known sample for the tag.

Expected Behavior
The output should correctly display ABC.PV for the tag field if the interpolation value (interp) is correctly computed.

Screenshots

Environment (please complete the following information):
TDEngine version 3.3.4.8

Thank you very much!

[yu285]

let me check on this

[itepifanio]

Hi @yu285, thank you for taking the time to address this! It seems that the issue hasn't been resolved in the latest release. Could you share any updates or progress on this?

[yu285]

Hi @yu285, thank you for taking the time to address this! It seems that the issue hasn't been resolved in the latest release. Could you share any updates or progress on this?

could you provide us the taosdump output ? we can check this from local

[yu285]

taosdump -o path databasename sensors

[mesquita]

Hi @yu285, sure, here's a representative dump of the database: Google Drive Link or WeTranfer Link.

You can reproduce the bug by running:

select _irowts as `time`, `tag`, interp(`value`) as `value` 
from sensors where `tag` in ('TAG-1234-01.PV') 
partition by tbname 
range('2024-12-01 00:00:00', '2025-01-01 00:00:00') 
every(600s) fill(prev);

Thank you sir!

[mesquita]

Hi @yu285, do you have any news on this one? Thanks!!

[yu285]

Hi @yu285, do you have any news on this one? Thanks!!

checking

[yu285]

we are fixing this ,will fix it in the next version in the end of the Feb.

or you can compile it by yourself once the PR is merged

we will inform you here .

[mesquita]

@yu285 thank you sir!