[CALCITE-6788] LoptOptimizeJoinRule should delegate costs to optimization planner #4148
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
|
zabetak
added
the
discussion-in-jira
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
LoptOptimizeJoinRuleuses 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 oncall.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.