perf: Reduce number of queries. Remove unneeded methods. Combine

subcategory and measure queries in controller

app/controllers/overview_controller.rb

@@ -25,10 +25,10 @@ class OverviewController < SqmApplicationController
   end
 
   def measures
-    @measures ||= Measure.all.includes(%i[scales admin_data_items category subcategory survey_items])
+    @measures ||= subcategories.flat_map(&:measures)
   end
 
   def subcategories
-    @subcategories ||= Subcategory.all.includes(:measures)
+    @subcategories ||= Subcategory.all.includes(%i[measures admin_data_items category])
   end
 end

app/models/measure.rb

@@ -192,34 +192,16 @@ class Measure < ActiveRecord::Base
 
   def sufficient_student_data?(school:, academic_year:)
     return false unless includes_student_survey_items?
-    return false if no_student_responses_exist?(school:, academic_year:)
 
     subcategory.response_rate(school:, academic_year:).meets_student_threshold?
   end
 
   def sufficient_teacher_data?(school:, academic_year:)
     return false unless includes_teacher_survey_items?
-    return false if no_teacher_responses_exist?(school:, academic_year:)
 
     subcategory.response_rate(school:, academic_year:).meets_teacher_threshold?
   end
 
-  def no_student_responses_exist?(school:, academic_year:)
-    @no_student_responses_exist ||= Hash.new do |memo, (school, academic_year)|
-      memo[[school, academic_year]] =
-        SurveyItemResponse.where(school:, academic_year:, survey_item: survey_items.student_survey_items).count.zero?
-    end
-    @no_student_responses_exist[[school, academic_year]]
-  end
-
-  def no_teacher_responses_exist?(school:, academic_year:)
-    @no_teacher_responses_exist ||= Hash.new do |memo, (school, academic_year)|
-      memo[[school, academic_year]] =
-        SurveyItemResponse.where(school:, academic_year:, survey_item: survey_items.teacher_survey_items).count.zero?
-    end
-    @no_teacher_responses_exist[[school, academic_year]]
-  end
-
   def incalculable_score(school:, academic_year:)
     @incalculable_score ||= Hash.new do |memo, (school, academic_year)|
       lacks_sufficient_survey_data = !sufficient_student_data?(school:, academic_year:) &&

app/models/subcategory.rb

@@ -5,6 +5,9 @@ class Subcategory < ActiveRecord::Base
 
   has_many :measures
   has_many :survey_items, through: :measures
+  has_many :admin_data_items, through: :measures
+  has_many :survey_items, through: :measures
+  has_many :scales, through: :measures
 
   def score(school:, academic_year:)
     measures.map do |measure|

app/models/teacher_response_rate_calculator.rb

@@ -2,11 +2,15 @@
 
 class TeacherResponseRateCalculator < ResponseRateCalculator
   def survey_item_count
-    @survey_item_count ||= @subcategory.measures.map do |measure|
-      measure.teacher_survey_items.reject do |survey_item|
-        survey_item.survey_item_responses.where(school:, academic_year:).none?
-      end.count
-    end.sum
+    @survey_item_count ||= begin
+      survey_items = @subcategory.measures.flat_map(&:teacher_survey_items)
+
+      SurveyItem.joins('inner join survey_item_responses on  survey_item_responses.survey_item_id = survey_items.id')
+                .teacher_survey_items
+                .where("survey_item_responses.school": school, "survey_item_responses.academic_year": academic_year, "survey_item_responses.survey_item_id": survey_items)
+                .group('survey_items.id')
+                .having('count(*) >= 0').count.length
+    end
   end
 
   def survey_items_have_sufficient_responses?

app/presenters/variance_chart_row_presenter.rb

@@ -12,7 +12,7 @@ class VarianceChartRowPresenter
     @meets_student_threshold = score.meets_student_threshold?
     @measure_name = @measure.name
     @measure_id = @measure.measure_id
-    @category = @measure.category
+    @category = @measure.subcategory.category
   end
 
   def sufficient_data?