[Bug]: Cannot merge two chunks when their time ranges have a gap

[pantonis]

What type of bug is this?

Other

What subsystems and features are affected?

Other

What happened?

I have two chunks with range start, range end. Hypertable range interval is set to 180 days

range_start	range_end
24/04/2017 03:00:00.000000 +03:00 	21/10/2017 03:00:00.000000 +03:00 
29/04/2016 03:00:00.000000 +03:00 	26/10/2016 03:00:00.000000 +03:00

When I try to merge them I get

cannot create new chunk partition boundaries

TimescaleDB version affected

2.18.2

PostgreSQL version used

16.8

What operating system did you use?

Ubuntu 24.04.1

What installation method did you use?

Deb/Apt

What platform did you run on?

On prem/Self-hosted

Relevant log output and stack trace

How can we reproduce the bug?

N/A

[antekresic]

This is a known limitation. Can you create the chunks that are in the gap? They can be empty and then you can merge them all together.

[pantonis]

How can you create chunks?

[antekresic]

One workaround I know of is to insert a single tuple in that time range and then immediately delete it, you will have the chunk created without any data in it.

That's the only way I'm aware of.

[pantonis]

Although it might work, not a clean solution I think. Since merging of compressed chunks is coming to 2.19, I think this issue need to be resolved properly. This is the purpose of the issue opened after talking with Freedman

[antekresic]

I agree, that's why I said its a known limitation. Can't speak for the plans on improvements but it should be fixed in the future (since we are aware of it).

Just offering you a workaround while the improvement comes.