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https://issues.apache.org/jira/browse/CALCITE-4522?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17300770#comment-17300770
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Vladimir Sitnikov commented on CALCITE-4522:
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[~julianhyde], the PR is in perfect shape for 3 days.
https://github.com/apache/calcite/pull/2363/commits/18cf22922bea7f1657f704e6fd7a1e6335b39240
is wonderful.
It looks like it is you who hold up the merge.
{quote}I am vetoing this PR until we sort this out{quote}
A veto without a justification is invalid and has no weight.
Could you please justify the veto?
The PR is already good, no new reviews since the last 3 days, so I believe it
is worth committing.
I do not understand why do you think I hold up someone.
> Sort cost should account for the number of columns in collation
> ---------------------------------------------------------------
>
> Key: CALCITE-4522
> URL: https://issues.apache.org/jira/browse/CALCITE-4522
> Project: Calcite
> Issue Type: Improvement
> Components: core
> Reporter: hqx
> Priority: Minor
> Labels: pull-request-available
> Time Spent: 9h 20m
> Remaining Estimate: 0h
>
> The old method to compute the cost of sort has some problem.
> # When the RelCollation is empty, there is no need to sort, but it still
> compute the cpu cost of sort.
> # use n * log\(n) * row_byte to estimate the cpu cost may be inaccurate,
> where n means the output row count of the sort operator, and row_byte means
> the average bytes of one row .
> Instead, I give follow suggestion.
> # the cpu cost is zero if the RelCollation is empty.
> # let heap_size be min\(offset + output_count, input_count), and use
> input_count * log\(heap_size)* row_byte to compute the cpu cost.
> When fetch is zero, I found the output_count is 1 not 0. This conveniently
> ensure the log\(heap_size) no less than zero
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