[jira] [Updated] (IGNITE-16013) Calcite engine. Introduce sort-with-limit physical relational operator

["Aleksey Plekhanov (Jira)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/IGNITE-16013?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Aleksey Plekhanov updated IGNITE-16013:
---------------------------------------
    Labels: calcite calcite3-required  (was: calcite3-required)

> Calcite engine. Introduce sort-with-limit physical relational operator
> ----------------------------------------------------------------------
>
>                 Key: IGNITE-16013
>                 URL: https://issues.apache.org/jira/browse/IGNITE-16013
>             Project: Ignite
>          Issue Type: Improvement
>            Reporter: Aleksey Plekhanov
>            Assignee: Vladimir Steshin
>            Priority: Major
>              Labels: calcite, calcite3-required
>             Fix For: 2.14
>
>          Time Spent: 7h 50m
>  Remaining Estimate: 0h
>
> Currently, sort and limit are different physical relational operators, but in some cases, sort combined with a limit can be more effective. For example {{ORDER BY x LIMIT 1}} requires to store only one row and can be processed with {{O(rowsCount)}} operations. In general. {{ORDER BY x LIMIT m}} requires {{O(min(rowsCount, m))}} memory and have {{O(rowsCount * ln(min(rowsCount, m)))}} complexity.
> Since {{Limit}} node can't be moved below the {{Exchange}} node, {{ORDER BY x LIMIT m}} clause should produce two nodes: {{Limit}} node, with single distribution, and {{SortWithLimit}} node, which can be moved below the {{Exchange}} node and can reduce network traffic.



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