diff --git a/app/models/badge.rb b/app/models/badge.rb
index ed97216c782..af0c054d66a 100644
--- a/app/models/badge.rb
+++ b/app/models/badge.rb
@@ -1,6 +1,9 @@
 # frozen_string_literal: true
 
 class Badge < ActiveRecord::Base
+  # TODO: Drop in July 2021
+  self.ignored_columns = %w{image}
+
   include GlobalPath
   include HasSanitizableFields
 
diff --git a/app/models/category.rb b/app/models/category.rb
index 57a15bc62d8..ad5a662a356 100644
--- a/app/models/category.rb
+++ b/app/models/category.rb
@@ -5,6 +5,11 @@ class Category < ActiveRecord::Base
     'none'
   ]
 
+  # TODO(2020-11-18): remove
+  self.ignored_columns = %w{
+    suppress_from_latest
+  }
+
   include Searchable
   include Positionable
   include HasCustomFields
diff --git a/app/models/directory_column.rb b/app/models/directory_column.rb
index aa4324345a3..3a290432c2f 100644
--- a/app/models/directory_column.rb
+++ b/app/models/directory_column.rb
@@ -2,6 +2,8 @@
 
 class DirectoryColumn < ActiveRecord::Base
 
+  # TODO(2021-06-18): Remove automatic column
+  self.ignored_columns = ["automatic"]
   self.inheritance_column = nil
 
   enum type: { automatic: 0, user_field: 1, plugin: 2 }, _scopes: false
diff --git a/app/models/email_token.rb b/app/models/email_token.rb
index 77156125e53..1178352523a 100644
--- a/app/models/email_token.rb
+++ b/app/models/email_token.rb
@@ -35,6 +35,9 @@ class EmailToken < ActiveRecord::Base
     end
   end
 
+  # TODO(2022-01-01): Remove
+  self.ignored_columns = %w{token}
+
   def self.scopes
     @scopes ||= Enum.new(
       signup: 1,
diff --git a/app/models/embeddable_host.rb b/app/models/embeddable_host.rb
index 6b2d2a9b4bd..212348bc3d1 100644
--- a/app/models/embeddable_host.rb
+++ b/app/models/embeddable_host.rb
@@ -10,6 +10,9 @@ class EmbeddableHost < ActiveRecord::Base
     self.host.sub!(/\/.*$/, '')
   end
 
+  # TODO(2021-07-23): Remove
+  self.ignored_columns = ["path_whitelist"]
+
   def self.record_for_url(uri)
 
     if uri.is_a?(String)
diff --git a/app/models/invite.rb b/app/models/invite.rb
index ff4a4521e1d..52c0a97b425 100644
--- a/app/models/invite.rb
+++ b/app/models/invite.rb
@@ -8,6 +8,12 @@ class Invite < ActiveRecord::Base
   include RateLimiter::OnCreateRecord
   include Trashable
 
+  # TODO(2021-05-22): remove
+  self.ignored_columns = %w{
+    user_id
+    redeemed_at
+  }
+
   BULK_INVITE_EMAIL_LIMIT = 200
   DOMAIN_REGEX = /\A(([a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9\-]*[a-zA-Z0-9])\.)+([A-Za-z0-9]|[A-Za-z0-9][A-Za-z0-9\-]*[A-Za-z0-9])\z/
 
diff --git a/app/models/post.rb b/app/models/post.rb
index 5db38ad4a7c..04df7e932fc 100644
--- a/app/models/post.rb
+++ b/app/models/post.rb
@@ -10,6 +10,11 @@ class Post < ActiveRecord::Base
   include HasCustomFields
   include LimitedEdit
 
+  self.ignored_columns = [
+    "avg_time", # TODO(2021-01-04): remove
+    "image_url" # TODO(2021-06-01): remove
+  ]
+
   cattr_accessor :plugin_permitted_create_params, :plugin_permitted_update_params
   self.plugin_permitted_create_params = {}
   self.plugin_permitted_update_params = {}
diff --git a/app/models/topic.rb b/app/models/topic.rb
index 751a82a5327..1a6948c6cc6 100644
--- a/app/models/topic.rb
+++ b/app/models/topic.rb
@@ -11,6 +11,11 @@ class Topic < ActiveRecord::Base
   include LimitedEdit
   extend Forwardable
 
+  self.ignored_columns = [
+    "avg_time", # TODO(2021-01-04): remove
+    "image_url" # TODO(2021-06-01): remove
+  ]
+
   def_delegator :featured_users, :user_ids, :featured_user_ids
   def_delegator :featured_users, :choose, :feature_topic_users
 
diff --git a/app/models/topic_timer.rb b/app/models/topic_timer.rb
index 5e80b5d4edd..2a9a690adef 100644
--- a/app/models/topic_timer.rb
+++ b/app/models/topic_timer.rb
@@ -3,6 +3,10 @@
 class TopicTimer < ActiveRecord::Base
   MAX_DURATION_MINUTES = 20.years.to_i / 60
 
+  self.ignored_columns = [
+    "duration" # TODO(2021-06-01): remove
+  ]
+
   include Trashable
 
   belongs_to :user
diff --git a/app/models/topic_user.rb b/app/models/topic_user.rb
index dcb0f294164..4f6b7853dde 100644
--- a/app/models/topic_user.rb
+++ b/app/models/topic_user.rb
@@ -1,6 +1,10 @@
 # frozen_string_literal: true
 
 class TopicUser < ActiveRecord::Base
+  self.ignored_columns = [
+    :highest_seen_post_number # Remove after 01 Jan 2022
+  ]
+
   belongs_to :user
   belongs_to :topic
 
diff --git a/app/models/upload.rb b/app/models/upload.rb
index 29c2b5d60c2..d0611ba84af 100644
--- a/app/models/upload.rb
+++ b/app/models/upload.rb
@@ -3,6 +3,10 @@
 require "digest/sha1"
 
 class Upload < ActiveRecord::Base
+  self.ignored_columns = [
+    "verified" # TODO(2020-12-10): remove
+  ]
+
   include ActionView::Helpers::NumberHelper
   include HasUrl
 
diff --git a/app/models/user_api_key.rb b/app/models/user_api_key.rb
index f20e75c575f..d0238781bc7 100644
--- a/app/models/user_api_key.rb
+++ b/app/models/user_api_key.rb
@@ -1,6 +1,10 @@
 # frozen_string_literal: true
 
 class UserApiKey < ActiveRecord::Base
+  self.ignored_columns = [
+    "scopes" # TODO(2020-12-18): remove
+  ]
+
   REVOKE_MATCHER = RouteMatcher.new(actions: "user_api_keys#revoke", methods: :post, params: [:id])
 
   belongs_to :user
diff --git a/app/models/user_stat.rb b/app/models/user_stat.rb
index 89abd01e0ce..7d0093eeadc 100644
--- a/app/models/user_stat.rb
+++ b/app/models/user_stat.rb
@@ -4,6 +4,9 @@ class UserStat < ActiveRecord::Base
   belongs_to :user
   after_save :trigger_badges
 
+  # TODO(2021-05-13): Remove
+  self.ignored_columns = ["topic_reply_count"]
+
   def self.ensure_consistency!(last_seen = 1.hour.ago)
     reset_bounce_scores
     update_distinct_badge_count