perf: coalesce single-column sort runs to cut merge fan-in
- Dominant language
- Rust
- Stars
- 9.3k
- Forks
- 2.4k
- Avg merge
- 3d 7h
- Merged PRs (30d)
- 344
Description
### Is your feature request related to a problem or challenge?
Columns that exceed the threshold are merged using merge.
This causes a lot of small sort runs to be merged, which is slower than larger runs.
For multi column the tradeoff is different as multi row sort using lexsort_to_indices is slower.
### Describe the solution you'd like
Coalesce single columns until the threshold (1MiB by default)
_No response_
### Describe alternatives you've considered
_No response_
### Additional context
_No response_
Contributor guide
Research direction
No file or test is named. Start by locating the merge path for sort runs that exceed the 1 MiB threshold and compare the single-column and multi-column cases. Done means single-column runs are coalesced up to the threshold while preserving the existing multi-column tradeoff and reducing merge fan-in.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- rust
- Domain
- performance
- Issue type
- Feature
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Quiet
- Clarity
- Mostly clear
- Newbie friendliness
- 48/100