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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. -- This message was sent by Atlassian Jira (v8.20.7#820007)