1 files changed, 17 insertions, 3 deletions
diff --git a/lib/gitlab/background_migration/remove_duplicate_vulnerabilities_findings.rb b/lib/gitlab/background_migration/remove_duplicate_vulnerabilities_findings.rb
index ca61118a06c..15799659b55 100644
--- a/lib/gitlab/background_migration/remove_duplicate_vulnerabilities_findings.rb
+++ b/lib/gitlab/background_migration/remove_duplicate_vulnerabilities_findings.rb
@@ -2,7 +2,7 @@
 
 # rubocop: disable Style/Documentation
 class Gitlab::BackgroundMigration::RemoveDuplicateVulnerabilitiesFindings
-  DELETE_BATCH_SIZE = 100
+  DELETE_BATCH_SIZE = 50
 
   # rubocop:disable Gitlab/NamespacedClass
   class VulnerabilitiesFinding < ActiveRecord::Base
@@ -10,6 +10,12 @@ class Gitlab::BackgroundMigration::RemoveDuplicateVulnerabilitiesFindings
   end
   # rubocop:enable Gitlab/NamespacedClass
 
+  # rubocop:disable Gitlab/NamespacedClass
+  class Vulnerability < ActiveRecord::Base
+    self.table_name = "vulnerabilities"
+  end
+  # rubocop:enable Gitlab/NamespacedClass
+
   def perform(start_id, end_id)
     batch = VulnerabilitiesFinding.where(id: start_id..end_id)
 
@@ -40,11 +46,19 @@ class Gitlab::BackgroundMigration::RemoveDuplicateVulnerabilitiesFindings
       ids_to_delete.concat(duplicate_ids)
 
       if ids_to_delete.size == DELETE_BATCH_SIZE
-        VulnerabilitiesFinding.where(id: ids_to_delete).delete_all
+        delete_findings_and_vulnerabilities(ids_to_delete)
         ids_to_delete.clear
       end
     end
 
-    VulnerabilitiesFinding.where(id: ids_to_delete).delete_all if ids_to_delete.any?
+    delete_findings_and_vulnerabilities(ids_to_delete) if ids_to_delete.any?
+  end
+
+  private
+
+  def delete_findings_and_vulnerabilities(ids)
+    vulnerability_ids = VulnerabilitiesFinding.where(id: ids).pluck(:vulnerability_id).compact
+    VulnerabilitiesFinding.where(id: ids).delete_all
+    Vulnerability.where(id: vulnerability_ids).delete_all
   end
 end