apache / apache/iotdb

[Bug] There is a logical error in the comparison operator.

Open
#14,139 2 comments 0 reactions 0 assignees View on GitHub
Dominant language
Java
Stars
6.4k
Forks
1.2k
Avg merge
1d 23h
Merged PRs (30d)
115

Description

### Search before asking

- [X] I searched in the [issues](https://github.com/apache/iotdb/issues) and found nothing similar.

### Version

version 1.3.3 (Build: ad95a7e)

### Describe the bug and provide the minimal reproduce step

```
DROP DATABASE root.db0
CREATE DATABASE root.db0

CREATE TIMESERIES root.db0.t1 WITH datatype=DOUBLE 'MAX_POINT_NUMBER'='8';
INSERT INTO root.db0(timestamp, t1) VALUES (1685589672533, 0.01);
INSERT INTO root.db0(t1) VALUES (0.02);

# query 1
SELECT t1 AS ref0 FROM root.db0 WHERE 0.02 <= t1 AND t1 <= 0.03

# query 2
SELECT t1 AS ref0 FROM root.db0 WHERE 0.01 <= t1 AND t1 <= 0.03

# query 3
SELECT t1 AS ref0 FROM root.db0 WHERE 1 < time

# query 3 success
SELECT t1 AS ref0 FROM root.db0 WHERE t1 >= 0.01 AND t1 <= 0.03
```

### What did you expect to see?

Query 1 returned result set: 0.02

Query 2 returned result set: 0.01 and 0.02

Query 3 returned result set: 0.01 and 0.02

Query 4 returned result set: 0.01 and 0.02

### What did you see instead?

Query 1 returned result set: 0.01 and 0.02

Query 2 returned result set: 0.02

Query 3 returned result set: **Empty set.**

Query 4 returned result set: 0.01 and 0.02

### Anything else?

Dear IoTDB team, I believe this is a logical bug. When the comparison operator is in the form of `constant <= column`, the correct result set cannot be returned.

### Are you willing to submit a PR?

- [X] I'm willing to submit a PR!

Contributor guide

Open the contributing guide

Research direction

Start by reproducing the reported comparison cases against IoTDB 1.3.3, especially predicates with a constant on the left such as `0.02 <= t1` and `1 < time`. Trace the comparison handling used by these SQL predicates and add regression coverage for the expected result sets. Done means both operand orders return equivalent, correct results while the existing `t1 >= 0.01` form remains correct.

Written by the indexing model from the issue text.

Assessment

Tech stack
java, sql
Domain
databases
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
42/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.