doc: Add documentation for pushing limit into plan#20271
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2010YOUY01 wants to merge 2 commits intoapache:mainfrom
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doc: Add documentation for pushing limit into plan#202712010YOUY01 wants to merge 2 commits intoapache:mainfrom
2010YOUY01 wants to merge 2 commits intoapache:mainfrom
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Feb 10, 2026
| //! [`LimitPushdown`] pushes `LIMIT` down through `ExecutionPlan`s to reduce | ||
| //! data transfer as much as possible. | ||
| //! | ||
| //! # Plan Limit Absorption |
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Maybe we can mention that with the use of LimitedBatchCoalescer this can allow for passing the limit down and allowing output immediately when the limit is reached.
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Good point, updated!
| //! --- DataSourceExec() | ||
| //! --- DataSourceExec() | ||
| //! ``` | ||
| //! Under this model, `NestedLoopJoinExec` would keep working until it can emit |
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Don't we want to give an example with an embedded limit?
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Updated, thanks.
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Which issue does this PR close?
Rationale for this change
Besides pushing
LimitExecdown the query plan, there is another optimization that allows plan nodes to absorb a limit, so it can potentially stop early.I’ve noticed that this form of limit absorption has not been implemented by many operators. This suggests the optimization is non-obvious, so I’d like to improve the documentation for it.
A recent PR that implements this optimization is:
What changes are included in this PR?
Are these changes tested?
Are there any user-facing changes?