Make issue_type index partial (incident only)

db/migrate/20200721043502_add_issue_type_index_to_issues.rb

@@ -6,8 +6,13 @@ class AddIssueTypeIndexToIssues < ActiveRecord::Migration[6.0]
   DOWNTIME = false
   disable_ddl_transaction!
 
+  INCIDENT_TYPE = 1
+  INDEX_NAME    = 'index_issues_on_incident_issue_type'
+
   def up
-    add_concurrent_index :issues, :issue_type
+    add_concurrent_index :issues,
+                         :issue_type, where: "issue_type = #{INCIDENT_TYPE}",
+                         name: INDEX_NAME
   end
 
   def down

db/structure.sql

@@ -19697,7 +19697,7 @@ CREATE INDEX index_issues_on_description_trigram ON public.issues USING gin (des
 
 CREATE INDEX index_issues_on_duplicated_to_id ON public.issues USING btree (duplicated_to_id) WHERE (duplicated_to_id IS NOT NULL);
 
-CREATE INDEX index_issues_on_issue_type ON public.issues USING btree (issue_type);
+CREATE INDEX index_issues_on_incident_issue_type ON public.issues USING btree (issue_type) WHERE (issue_type = 1);
 
 CREATE INDEX index_issues_on_last_edited_by_id ON public.issues USING btree (last_edited_by_id);