15,310 questions
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11
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Apache IoTDB date_bin fails with "mismatched input" for 1mo 1d interval
I'm trying to analyze server CPU metrics using a custom billing cycle that doesn't align with calendar months. Our billing department defines each period as "one full month plus one extra day&...
- 11
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47
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How to tell if a `NULL` value means "no data" or "no such sensor" in wildcard queries in Apache IoTDB?
I'm confused about NULL handling in Apache IoTDB 2.0.6 Tree Model. When using wildcard queries across multiple devices, missing timeseries show as NULL - but this looks identical to intentionally ...
- 43
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18
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Apache IoTDB 2.0.6: How to generate missing timestamps in Tree Model like Table Model's date_bin_gapfill?
Environment
Apache IoTDB 2.0.6 standalone, using Tree Model with 10TB historical data.
Business Scenario
Industrial monitoring requires fixed time grid queries. Every 5 seconds must have a record; ...
-4
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34
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Apache IoTDB 2.0.6: Sliding window with fixed number of points (holiday data missing leads to unstable sample count)
I am working with Apache IoTDB 2.0.6 and trying to compute a rolling moving average over time-series data.
My requirement:
Calculate aggregates over a sliding window that always contains a fixed ...
1
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0
answers
22
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Apache IoTDB HOP `Time` Window Calculation: Latest Data Not Included and Syntax Error
I am using Apache IoTDB 2.0.7 Table Model to calculate the 5-week moving average (MA5_Week) of stock closing prices.My goal: Calculate the average closing price of the latest 5 full trading weeks with ...
Tooling
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votes
3
replies
57
views
What classification models are suitable for time series data?
I have a raw time series dataset. Can I use classification models on time series data? If yes which classification models can I use without forecasting? Most examples I’ve seen focus on forecasting or ...
2
votes
1
answer
75
views
Confusing Behavior of ALL Subquery in Apache IoTDB
I'm using the ALL syntax in Apache IoTDB 2.0.6 table model for a query, but the returned result is inconsistent with expectations.
Minimal Reproducible Data
CREATE TABLE main_data (
`time` ...
- 31
1
vote
0
answers
25
views
How to use dynamic parameters with the date_bin function in Apache IoTDB
I'm using the table model of Apache IoTDB 2.0.6 and want to dynamically set the time interval for the date_bin function based on a configuration table. However, I found that the first parameter ...
- 21
1
vote
0
answers
32
views
Apache IoTDB Nested Query Error "correlated subquery is not supported"
I'm using the table model of Apache IoTDB 2.0.5 and trying to implement a query to find records higher than the average value of the same group. I need to use non-equality comparisons in the join ...
- 41
Tooling
0
votes
5
replies
90
views
Creating a tibble with specific information pulled out
I am working in r studio, looking specifically at the built-in R time-series `co2`: the monthly atmospheric CO2 concentration at Mauna Loa. My instructions are to create a tibble named `co2_df` with ...
2
votes
1
answer
47
views
Error when using COALESCE to handle NULL values
When using Apache IoTDB 2.0.6 with the table model, since the temperature data collected in our business scenario may contain NULL values, I considered using COALESCE to handle NULL values as 0 for ...
- 11
0
votes
1
answer
36
views
How to use MAX_BY function in Apache IoTDB to return all timestamps when temperature is at maximum?
In Apache IoTDB 2.0.6 table model, the MAX_BY function can return the timestamp when the data value is at its maximum. However, my requirement is to return all timestamps if multiple time points have ...
1
vote
0
answers
22
views
IoTDB 1.3.2: Results appear misaligned when using multiple aggregate functions together
When using DBeaver to connect to Apache IoTDB version 1.3.2 and execute queries, I discovered that when multiple aggregate functions are used in the same SQL statement, the returned results appear ...
- 31
0
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0
answers
50
views
SELECT INTO with :: placeholder fails in aggregation query - Apache IoTDB 2.0.6
In Apache IoTDB 2.0.6 (Tree Model), I'm trying to downsample data for all devices under a specified database and write the results back while preserving the device path structure. I wrote a SELECT ...
- 23
1
vote
0
answers
41
views
Error when creating Continuous Query in Apache IoTDB
I am trying to create a Continuous Query (CQ) in Apache IoTDB 2.0.6 Tree Model to meet my business query requirements. However, multiple attempts have failed with errors.
Attempt 1
CREATE CQ cq_1mxx
...
- 1