perf: add pghero and implement pghero suggestions. Remove unneeded indexes

Gemfile

@@ -81,6 +81,9 @@ group :development do
   gem "nested_scaffold"
   gem "rack-livereload"
   # gem 'reek', require: false
+  gem "dexter"
+  gem "pghero"
+  gem "pg_query", ">= 2"
   gem "rubocop", require: false
   gem "seed_dump"
   gem "solargraph-reek"

Gemfile.lock

@@ -137,6 +137,8 @@ GEM
       database_cleaner-core (~> 2.0.0)
     database_cleaner-core (2.0.1)
     date (3.3.4)
+    dexter (0.1.0)
+      trollop
     diff-lcs (1.5.0)
     docile (1.4.0)
     dotenv (2.8.1)
@@ -176,6 +178,7 @@ GEM
       activerecord (>= 4.0.0)
     globalid (1.2.1)
       activesupport (>= 6.1)
+    google-protobuf (3.25.1)
     guard (2.18.1)
       formatador (>= 0.2.4)
       listen (>= 2.7, < 4.0)
@@ -266,6 +269,10 @@ GEM
       ast (~> 2.4.1)
       racc
     pg (1.5.4)
+    pg_query (5.0.0)
+      google-protobuf (>= 3.22.3)
+    pghero (3.4.0)
+      activerecord (>= 6)
     pry (0.14.2)
       coderay (~> 1.1)
       method_source (~> 1.0)
@@ -428,6 +435,7 @@ GEM
     tilt (2.3.0)
     timecop (0.9.8)
     timeout (0.4.1)
+    trollop (2.9.10)
     turbo-rails (1.5.0)
       actionpack (>= 6.0.0)
       activejob (>= 6.0.0)
@@ -468,6 +476,7 @@ DEPENDENCIES
   cuprite
   database_cleaner
   devise!
+  dexter
   dotenv-rails
   ed25519
   erb_lint
@@ -486,6 +495,8 @@ DEPENDENCIES
   nokogiri
   parallel_tests
   pg
+  pg_query (>= 2)
+  pghero
   puma (>= 6.4.0)
   rack-livereload
   rack-mini-profiler

config/routes.rb

@@ -2,14 +2,16 @@ Rails.application.routes.draw do
   resources :districts do
     resources :schools, only: %i[index show] do
       resources :overview, only: [:index]
-      resources :categories, only: [:show], path: 'browse'
+      resources :categories, only: [:show], path: "browse"
       resources :analyze, only: [:index]
     end
   end
 
-  get :reports, to: 'reports#index'
-  get 'reports/gps', to: 'gps#index'
+  get :reports, to: "reports#index"
+  get "reports/gps", to: "gps#index"
 
-  get '/welcome', to: 'home#index'
-  root to: 'home#index'
+  get "/welcome", to: "home#index"
+  root to: "home#index"
+
+  # mount PgHero::Engine, at: "pghero" # remove in development env to see suggestions at localhost:3000/pghero
 end

db/migrate/20231227183313_remove_unneeded_indexes.rb

@@ -0,0 +1,9 @@
+class RemoveUnneededIndexes < ActiveRecord::Migration[7.1]
+  def change
+    remove_index :response_rates, name: "index_response_rates_on_school_id", column: :school_id
+    remove_index :student_races, name: "index_student_races_on_student_id", column: :student_id
+    remove_index :survey_item_responses, name: "index_survey_item_responses_on_school_id", column: :school_id
+    remove_index :survey_item_responses, name: "index_survey_item_responses_on_school_id_and_academic_year_id",
+                                         column: %i[school_id academic_year_id]
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[7.1].define(version: 2023_10_04_211430) do
+ActiveRecord::Schema[7.1].define(version: 2023_12_27_183313) do
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
 
@@ -360,7 +360,6 @@ ActiveRecord::Schema[7.1].define(version: 2023_10_04_211430) do
     t.datetime "updated_at", null: false
     t.index ["academic_year_id"], name: "index_response_rates_on_academic_year_id"
     t.index ["school_id", "subcategory_id"], name: "index_response_rates_on_school_id_and_subcategory_id"
-    t.index ["school_id"], name: "index_response_rates_on_school_id"
     t.index ["subcategory_id"], name: "index_response_rates_on_subcategory_id"
   end
 
@@ -421,7 +420,6 @@ ActiveRecord::Schema[7.1].define(version: 2023_10_04_211430) do
     t.datetime "updated_at", null: false
     t.index ["race_id"], name: "index_student_races_on_race_id"
     t.index ["student_id", "race_id"], name: "index_student_races_on_student_id_and_race_id"
-    t.index ["student_id"], name: "index_student_races_on_student_id"
   end
 
   create_table "students", force: :cascade do |t|
@@ -463,9 +461,7 @@ ActiveRecord::Schema[7.1].define(version: 2023_10_04_211430) do
     t.index ["income_id"], name: "index_survey_item_responses_on_income_id"
     t.index ["response_id"], name: "index_survey_item_responses_on_response_id"
     t.index ["school_id", "academic_year_id", "survey_item_id"], name: "by_school_year_and_survey_item"
-    t.index ["school_id", "academic_year_id"], name: "index_survey_item_responses_on_school_id_and_academic_year_id"
     t.index ["school_id", "survey_item_id", "academic_year_id", "grade"], name: "index_survey_responses_on_grade"
-    t.index ["school_id"], name: "index_survey_item_responses_on_school_id"
     t.index ["sped_id"], name: "index_survey_item_responses_on_sped_id"
     t.index ["student_id"], name: "index_survey_item_responses_on_student_id"
     t.index ["survey_item_id"], name: "index_survey_item_responses_on_survey_item_id"