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fix: return EmptyExec for LIMIT 0 in physical planning #30

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fix: return EmptyExec for LIMIT 0 in physical planning #30

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27 changes: 16 additions & 11 deletions datafusion/core/src/physical_planner.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -1238,20 +1238,25 @@ impl DefaultPhysicalPlanner {
);
};

// GlobalLimitExec requires a single partition for input
let input = if input.output_partitioning().partition_count() == 1 {
input
if let Some(0) = fetch {

@askalt askalt Aug 21, 2026

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nit: it seems match fetch would look more readable.

@askalt askalt Aug 21, 2026

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Are we ok with LIMIT 0?

@karpenkoag karpenkoag Aug 21, 2026

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without a placeholder?
Yes, it is OK.

// Return an empty exec node if the number of requested rows is 0
Arc::new(EmptyExec::new(input.schema()))
} else {
// Apply a LocalLimitExec to each partition. The optimizer will also insert
// a CoalescePartitionsExec between the GlobalLimitExec and LocalLimitExec
if let Some(fetch) = fetch {
Arc::new(LocalLimitExec::new(input, fetch + skip))
} else {
// GlobalLimitExec requires a single partition for input
let input = if input.output_partitioning().partition_count() == 1 {
input
}
};
} else {
// Apply a LocalLimitExec to each partition. The optimizer will also insert
// a CoalescePartitionsExec between the GlobalLimitExec and LocalLimitExec
if let Some(fetch) = fetch {
Arc::new(LocalLimitExec::new(input, fetch + skip))
} else {
input
}
};

Arc::new(GlobalLimitExec::new(input, skip, fetch))
Arc::new(GlobalLimitExec::new(input, skip, fetch))
}
}
LogicalPlan::Unnest(Unnest {
list_type_columns,
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