influxdb3 client fails when querying table with tags containing empty values

[jnativio2]

I have a downsampler plugin for a table that has columns (tags) that have empty values for some records. The query is like this:

2025-08-13 16-05-00 [INFO] [19d3aa9e-0fcd-4ac2-a1db-2d03c4839dc1] Executing query: SELECT DATE_BIN(INTERVAL '10 minutes', time, '1970-01-01T00:00:00Z') AS _time, count(*) AS record_count, MIN(time) AS time_from, MAX(time) AS time_to, avg("usage_idle") as "usage_idle_avg", "cpu", "datacenter", "env", "host", "instance", "objectname", "os", "pool", "server_role", "source" FROM 'infra_cpu' WHERE time >= '2025-08-13T20:00:00Z' AND time < '2025-08-13T20:05:00Z' GROUP BY _time, cpu, datacenter, env, host, instance, objectname, os, pool, server_role, source

It fails every run with this message in the plugin:

2025-08-12 12-00-00 [ERROR] error running scheduled plugin: Join error, please report: task 203459 panicked with message "Trying to access an element at index 0 from a StringArray of length 0"

in influxdb3.log:

level=error msg="Thread panic" panic_type=unknown panic_message="Trying to access an element at index 0 from a StringArray of length 0" panic_file=/usr/local/cargo/git/checkouts/arrow-rs-db36434c601cf8eb/eae176c/arrow-array/src/array/byte_array.rs panic_line=305 panic_column=9 target="panic_logging" location="/usr/local/cargo/git/checkouts/influxdb3_core-2ede6fca005e1dcf/ad3a2b2/panic_logging/src/lib.rs:58" ts=2025-08-14T13:15:00.084914Z time=1755177300084914569

That query runs fine on CLI. Tried different tables with the same characteristic of having empty values for some tags and got the same result.

[hiltontj]

@jnativio2 can you provide the query result when using the CLI?

[jnativio2]

Sure. It is attached. I added an extra filter to reduce the size of the results. As you can see, some tags have empty values depending on the host being a windows or linux.

query_results.txt

[hiltontj]

Thanks @jnativio2 I opened influxdata/influxdb#26759 for us to look into this.