[jira] [Comment Edited] (CALCITE-2044) Tweak cost of BindableTableScan to make sure Project is pushed through Aggregate

["Alexey Roytman (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/CALCITE-2044?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16243875#comment-16243875 ] 

Alexey Roytman edited comment on CALCITE-2044 at 11/8/17 1:11 PM:
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The cost formula shall be an implementable policy.
I.e. if I implement an "{{XTable implements ProjectableFilterableTable}}" and also "{{implements ProjectableFilterableCostEstimator}}" then XTable has a function to estimate this behavior.
Or, we may wish to have an {{AbstractProjectableFilterable}} with such cost function (parameters like in {{ProjectableFilterableTable.scan()}}).

Anyway, project presence is better than project absence, and filter presence is better than filter absence... This seems to be more universal mantra.


was (Author: alexeyroytman):
The cost formula shall be an implementable policy.
I.e. if I implement an "{{\XTable implements ProjectableFilterableTable\}}" and also "{{\implements ProjectableFilterableCostEstimator\}}" then XTable has a function to estimate this behavior.
Or, we may wish to have an {{\AbstractProjectableFilterable\}} with such cost function (parameters like in {{\ProjectableFilterableTable.scan()\}}).

Anyway, project presence is better than project absence, and filter presence is better than filter absence... This seems to be more universal mantra.

> Tweak cost of BindableTableScan to make sure Project is pushed through Aggregate
> --------------------------------------------------------------------------------
>
>                 Key: CALCITE-2044
>                 URL: https://issues.apache.org/jira/browse/CALCITE-2044
>             Project: Calcite
>          Issue Type: Bug
>          Components: core
>            Reporter: Luis Fernando Kauer
>            Assignee: Julian Hyde
>            Priority: Minor
>
> Similar to [CALCITE-1876].
> Projects are not pushed to BindableTableScan when using ProjectableFilterableTable with aggregate functions.
> The reason is that the cost of BindableTableScan does not use projects (and filters), so the planner chooses a plan with Project node removed by ProjectRemoveRule.
> By tweaking the cost to use the number of used projects solved the problem.
> Any suggestion on the cost formula to take both projects and filters into account?



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