_read_deletes filters the full delete table once per distinct file_path
Nobody has claimed this yet.
Assessment
- Difficulty
- 3/5
- Estimated time
- 1-2 days
- Newbie friendliness
- 68/100
- Issue type
- Refactor
- Clarity
- Mostly clear
- Activity status
- Active
- Tech stack
- python
- Domain
- data-engineering, performance
Research direction
Start at the _read_deletes implementation and inspect both the dictionary-comprehension branch and the ORC branch described in the issue. Trace how file_path and pos are represented, then verify that the result is equivalent while avoiding a full-table filter for every distinct path; add or run coverage for delete files containing many paths.
Written by the indexing model from the issue text.
Description
_read_deletes builds its result with a dict comprehension that filters the whole table once per distinct file_path:
{
file.as_py(): table.filter(pc.field("file_path") == file).column("pos")
for file in table.column("file_path").chunks[0].dictionary
}
Cost is therefore O(rows x distinct paths). A delete file with many distinct paths makes this quadratic. The ORC branch below has the same shape via unique().
Issue investigation generated via claude, reviewed by Sung, Kevin, Fokko.
- Dominant language
- Python
- Stars
- 1.1k
- Forks
- 589
- Avg merge
- 2d 2h
- Merged PRs (30d)
- 70
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