reduce db query in script_levels#show #18532
Merged
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
optimize `sections_as_student` query in `app_options`.
balderdash
approved these changes
Oct 20, 2017
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Outdated suggestions cannot be applied.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.
This PR optimizes a
sections_as_student-related query inapp_options.When an AR association is already loaded into memory (
sections_as_studentis explicitly included into thescript_controller#showaction following #18445), it requires one less query to scan the existing in-memory relation usingdetect(a synonym forfind) compared to creating another ActiveRecord query usingfind_by. (I am working on a proof-of-concept PR that allows ActiveRecord to catch and automatically optimize these cases, but it probably won't be production-ready for a while- if ever.)Part of ActiveRecord query optimization pass (see #18390).