Change the type of verification_checksum column

in package file table for efficient usage of DB space

db/migrate/20200409105455_change_verification_checksum_field_type_in_package_file.rb

+# frozen_string_literal: true
+
+class ChangeVerificationChecksumFieldTypeInPackageFile < ActiveRecord::Migration[6.0]
+  DOWNTIME = false
+
+  def up
+    # The use of this column is behind a feature flag that never got enabled,
+    # so it's safe to remove it in a normal migration
+    remove_column :packages_package_files, :verification_checksum, :string # rubocop:disable Migration/RemoveColumn
+    add_column :packages_package_files, :verification_checksum, :binary
+  end
+
+  def down
+    remove_column :packages_package_files, :verification_checksum, :binary
+    add_column :packages_package_files, :verification_checksum, :string
+  end
+end

db/migrate/20200409105456_add_checksum_index_to_package_file.rb

+# frozen_string_literal: true
+
+class AddChecksumIndexToPackageFile < ActiveRecord::Migration[6.0]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  def up
+    add_concurrent_index :packages_package_files, :verification_checksum, where: "(verification_checksum IS NOT NULL)", name: "packages_packages_verification_checksum_partial"
+  end
+
+  def down
+    remove_concurrent_index :packages_package_files, :verification_checksum
+  end
+end

db/structure.sql

@@ -4668,9 +4668,9 @@ CREATE TABLE public.packages_package_files (
     file_sha256 bytea,
     verification_retry_at timestamp with time zone,
     verified_at timestamp with time zone,
-    verification_checksum character varying(255),
     verification_failure character varying(255),
-    verification_retry_count integer
+    verification_retry_count integer,
+    verification_checksum bytea
 );
 
 CREATE SEQUENCE public.packages_package_files_id_seq
@@ -13738,6 +13738,8 @@ COPY "schema_migrations" (version) FROM STDIN;
 20200408175424
 20200408212219
 20200409085956
+20200409105455
+20200409105456
 20200409211607
 20200410104828
 20200410232012

doc/development/geo/framework.md

@@ -324,7 +324,7 @@ Widgets should now be replicated by Geo!
      def change
        add_column :widgets, :verification_retry_at, :datetime_with_timezone
        add_column :widgets, :verified_at, :datetime_with_timezone
-       add_column :widgets, :verification_checksum, :string
+       add_column :widgets, :verification_checksum, :binary, using: 'verification_checksum::bytea'
        add_column :widgets, :verification_failure, :string
        add_column :widgets, :verification_retry_count, :integer
      end

ee/lib/gitlab/geo/replicable_model.rb

@@ -5,6 +5,7 @@ module Gitlab
     module ReplicableModel
       extend ActiveSupport::Concern
       include Checksummable
+      include ::ShaAttribute
 
       included do
         # If this hook turns out not to apply to all Models, perhaps we should extract a `ReplicableBlobModel`
@@ -12,6 +13,8 @@ module Gitlab
 
         scope :checksummed, -> { where('verification_checksum IS NOT NULL') }
         scope :checksum_failed, -> { where('verification_failure IS NOT NULL') }
+
+        sha_attribute :verification_checksum
       end
 
       class_methods do

ee/spec/lib/gitlab/geo/replicator_spec.rb

@@ -10,7 +10,9 @@ describe Gitlab::Geo::Replicator do
 
   before(:all) do
     ActiveRecord::Schema.define do
-      create_table :dummy_models
+      create_table :dummy_models, force: true do |t|
+        t.binary :verification_checksum
+      end
     end
   end
 
@@ -70,6 +72,8 @@ describe Gitlab::Geo::Replicator do
 
           with_replicator Geo::DummyReplicator
         end
+
+        DummyModel.reset_column_information
       end
 
       subject { DummyModel.new }