[
https://issues.apache.org/jira/browse/CALCITE-6788?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17913672#comment-17913672
]
Ruben Q L commented on CALCITE-6788:
------------------------------------
bq. Possibly the safest option would be to make the intermediate costing
configurable at the rule's level [...] and keeping the current behavior as the
default one.
Agree
> LoptOptimizeJoinRule should delegate costs to optimization planner
> ------------------------------------------------------------------
>
> Key: CALCITE-6788
> URL: https://issues.apache.org/jira/browse/CALCITE-6788
> Project: Calcite
> Issue Type: Improvement
> Components: core
> Affects Versions: 1.38.0
> Reporter: Claude Brisson
> Priority: Major
> Labels: pull-request-available
>
> {{LoptOptimizeJoinRule}} uses costs comparisons to recursively decide whether
> to add a join at the top of the joins tree or to push it down.
> When doing so, instead of directly calling {{mq.getCumulativeCost(rel)}}, it
> should rely on {{call.getPlanner.getCost(rel, mq)}}, which will be used
> thereafter to choose the best joins tree.
> This way, it becomes possible to customize the costs computation during the
> heuristic joins ordering phase by just overriding the {{getCost()}} method of
> the optimization planner.
> Without this patch, it is only possible to alter joins costs at the final
> phase of the algorithm, which defeats the goal of customizing them, including
> during the to-top/push-down phase.
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
