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Remove workaround for COUNT(*) in subquery decorrelation code #10553
Description
Is your feature request related to a problem or challenge?
While working on #10500 I found reference to "the count" bug in the code but it wasn't clear it was tracked by any ticket
@comphead figured out #10500 (comment) that if the relevant workaround is disabled, then the following query is incorrect:
Running "subquery.slt"
External error: query result mismatch:
[SQL] SELECT t1_id, (SELECT count(*) FROM t2 WHERE t2.t2_int = t1.t1_int) from t1
[Diff] (-expected|+actual)
11 1
- 22 0
+ 22 NULL
33 3
- 44 0
+ 44 NULL
at test_files/subquery.slt:763
Describe the solution you'd like
Remove the workaround / handle the issue correctly
I am not quite sure what this means (maybe @mingmwang can provide more details if he has time)
Describe alternatives you've considered
No response
Additional context
No response
Activity
[-]REmove workaround for 1COUNT(*)` in subquery decorrelation code[/-][+]REmove workaround for `COUNT(*)` in subquery decorrelation code[/+][-]REmove workaround for `COUNT(*)` in subquery decorrelation code[/-][+]Remove workaround for `COUNT(*)` in subquery decorrelation code[/+]suibianwanwank commentedon Mar 5, 2025
Hi, @alamb. I described the "count-bug" bug in #15032. Maybe I can try to optimize this comment~
suibianwanwank commentedon Mar 7, 2025
@alamb I have submitted a PR. When you have time, greatly appreciate your review. As I am new to DataFusion, any feedback for improvement would be very helpful. Thank you.
alamb commentedon Mar 7, 2025
For anyone following along, from @suibianwanwank's PR I wanted to post this link here: