fix: fetch is missed during EnforceDistribution - #14207
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xudong963 wants to merge 7 commits into
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Which issue does this PR close?
EnforceDistributiongenerates invalid plan #14150Rationale for this change
The root of the bug is that if there is a SortPreservingMergeExec operator and it has the fetch, the method(
remove_dist_changing_operators) will remove it directly, and miss the fetch. So it's definitely a bug.IIUC, SortPreservingMergeExec only will be added after
EnforceSorting, so if we want to reproduce the bug,EnforceDistributionneeds to run afterEnforceSorting, the default physical optimizer has the order of rules:EnforceDistribution->EnforceSorting, so it won't trigger the bug(fetch is missed), but if we runEnforceDistributionagain afterEnforceSorting, the bug will surface.What the PR is doing is that it will remain the fetch of
SortPreservingMergeExecand add it back if necessary, as the comments of the method said:If they are necessary, they will be added in subsequent stages.What changes are included in this PR?
Avoid missing fetch during
EnforceDistribution.Are these changes tested?
YES
Are there any user-facing changes?
NO