[SPARK-35767] [SQL] Avoid executing child plan twice in CoalesceExec #32920
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ok to test |
dongjoon-hyun
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Jun 15, 2021
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+1, LGTM. This is a very old bug introduced by SPARK-22238 at 2.3.0.
Nice catch, @andygrove .
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cc @cloud-fan |
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+1 changes lgtm. |
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Kubernetes integration test starting |
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Thank you, @andygrove and @tgravescs . |
dongjoon-hyun
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### What changes were proposed in this pull request? `CoalesceExec` needlessly calls `child.execute` twice when it could just call it once and re-use the results. This only happens when `numPartitions == 1`. ### Why are the changes needed? It is more efficient to execute the child plan once rather than twice. ### Does this PR introduce _any_ user-facing change? No. ### How was this patch tested? There are no functional changes. This is just a performance optimization, so the existing tests should be sufficient to catch any regressions. Closes #32920 from andygrove/coalesce-exec-executes-twice. Authored-by: Andy Grove <andygrove73@gmail.com> Signed-off-by: Dongjoon Hyun <dongjoon@apache.org> (cherry picked from commit 1012967) Signed-off-by: Dongjoon Hyun <dongjoon@apache.org>
dongjoon-hyun
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Jun 15, 2021
### What changes were proposed in this pull request? `CoalesceExec` needlessly calls `child.execute` twice when it could just call it once and re-use the results. This only happens when `numPartitions == 1`. ### Why are the changes needed? It is more efficient to execute the child plan once rather than twice. ### Does this PR introduce _any_ user-facing change? No. ### How was this patch tested? There are no functional changes. This is just a performance optimization, so the existing tests should be sufficient to catch any regressions. Closes #32920 from andygrove/coalesce-exec-executes-twice. Authored-by: Andy Grove <andygrove73@gmail.com> Signed-off-by: Dongjoon Hyun <dongjoon@apache.org> (cherry picked from commit 1012967) Signed-off-by: Dongjoon Hyun <dongjoon@apache.org>
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Kubernetes integration test status success |
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Test build #139820 has finished for PR 32920 at commit
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late LGTM |
flyrain
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Sep 21, 2021
### What changes were proposed in this pull request? `CoalesceExec` needlessly calls `child.execute` twice when it could just call it once and re-use the results. This only happens when `numPartitions == 1`. ### Why are the changes needed? It is more efficient to execute the child plan once rather than twice. ### Does this PR introduce _any_ user-facing change? No. ### How was this patch tested? There are no functional changes. This is just a performance optimization, so the existing tests should be sufficient to catch any regressions. Closes apache#32920 from andygrove/coalesce-exec-executes-twice. Authored-by: Andy Grove <andygrove73@gmail.com> Signed-off-by: Dongjoon Hyun <dongjoon@apache.org> (cherry picked from commit 1012967) Signed-off-by: Dongjoon Hyun <dongjoon@apache.org>
fishcus
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Jan 12, 2022
### What changes were proposed in this pull request? `CoalesceExec` needlessly calls `child.execute` twice when it could just call it once and re-use the results. This only happens when `numPartitions == 1`. ### Why are the changes needed? It is more efficient to execute the child plan once rather than twice. ### Does this PR introduce _any_ user-facing change? No. ### How was this patch tested? There are no functional changes. This is just a performance optimization, so the existing tests should be sufficient to catch any regressions. Closes apache#32920 from andygrove/coalesce-exec-executes-twice. Authored-by: Andy Grove <andygrove73@gmail.com> Signed-off-by: Dongjoon Hyun <dongjoon@apache.org> (cherry picked from commit 1012967) Signed-off-by: Dongjoon Hyun <dongjoon@apache.org>
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What changes were proposed in this pull request?
CoalesceExecneedlessly callschild.executetwice when it could just call it once and re-use the results. This only happens whennumPartitions == 1.Why are the changes needed?
It is more efficient to execute the child plan once rather than twice.
Does this PR introduce any user-facing change?
No.
How was this patch tested?
There are no functional changes. This is just a performance optimization, so the existing tests should be sufficient to catch any regressions.