Fix right, full join handling when having multiple non-matching rows at the left side #845
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Dandandan
commented
Aug 9, 2021
| @@ -745,9 +747,12 @@ fn build_join_indexes( | |||
| &keys_values, | |||
| )? { | |||
| left_indices.append_value(i)?; | |||
| } else { | |||
| left_indices.append_null()?; | |||
| right_indices.append_value(row as u32)?; | |||
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This is the fix, instead of adding the (left=null, right) to every non-match, it does it only once at the end if there wasn't a single match.
Dandandan
changed the title
alamb
approved these changes
Aug 9, 2021
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Talk about a speedy bugfix 🐎 ! I barely filed the ticket and there is a fix ready :)
One thing that might help readability would be to rename from double negative (no_match false) to has_match or something
Nice work @Dandandan
Co-authored-by: Andrew Lamb <andrew@nerdnetworks.org>
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Which issue does this PR close?
Closes #843
Rationale for this change
Right and hull join had an error where if they wouldn't match multiple left side values, for each value it didn't match it would add a row. This is triggered by the change to #842 which maps any value to a 0 hash. Normally values and null values have different hashes, so they wouldn't have this problem.
Instead the correct behavior is to add a single row if it doesn't match any.
What changes are included in this PR?
Are there any user-facing changes?