[IOTDB-3364] Query stucked with null valued aligned timeseries

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.13.0
• Fix Version/s: master branch, 0.13.1
• Component/s: Core/Engine, Core/Query
• Labels: pull-request-available
• Sprint: 2022-5-QueryExecution
• Assignee: Yuan Tian
• Reporter: Eric Pai
• Created: 01/Jun/22 03:03
• Updated: 02/Jun/22 01:11
• Resolved: 01/Jun/22 09:17

Description

Repeat steps:

1. Create an aligned timeseries:

create aligned timeseries root.sg.d1(s1 int32); 

2. Insert with null value:

insert into root.sg.d1(time, s1) aligned values(1400, null); 

3. Select directly WITHOUT restarting the server.

select * from root.sg.d1; 

We can see that the select request is stucked and never ends.

My brief debug can see that the query is trapped in an infinite loop at

https://github.com/apache/iotdb/blob/master/server/src/main/java/org/apache/iotdb/db/query/reader/series/SeriesReader.java#L339-L341

For a deeper debugging, the Statistics of firstTimeseriesMetadata may be the suspect? I'm not sure whether it's the root cause.

Issue Links

• links to: GitHub Pull Request #6120
• links to: GitHub Pull Request #6131