codesnips

class Tag < ApplicationRecord
  has_many :taggings, dependent: :destroy

  scope :top, ->(limit = 20) {
    joins(:taggings)
      .group(Arel.sql("tags.id"))

module WriteAmplificationGuard
  extend ActiveSupport::Concern

  def update_if_changed(attrs)
    changed = attrs.each_with_object({}) do |(key, value), acc|
      cast = self.class.type_for_attribute(key.to_s).cast(value)

module DefensiveDeserialization
  extend ActiveSupport::Concern

  MissingRecord = Struct.new(:gid) do
    def missing?
      true

module RetryableTransaction
  module_function

  RETRIABLE = [ActiveRecord::Deadlocked, ActiveRecord::LockWaitTimeout].freeze

  def run(max_retries: 3, base_delay: 0.05, &block)

require "timeout"

module HealthCheck
  class Probe
    Result = Struct.new(:name, :status, :latency_ms, :critical, :error, keyword_init: true) do
      def healthy?

CREATE TABLE daily_events (
    id          BIGSERIAL PRIMARY KEY,
    category    TEXT        NOT NULL,
    item_id     BIGINT      NOT NULL,
    score       NUMERIC(10,2) NOT NULL DEFAULT 0,
    occurred_at TIMESTAMPTZ NOT NULL DEFAULT now()

class CreateTags < ActiveRecord::Migration[7.0]
  def change
    create_table :tags do |t|
      t.string :name, null: false
      t.integer :taggings_count, null: false, default: 0
      t.timestamps

class Article < ApplicationRecord
  scope :ranked, -> { order(score: :desc, id: :desc) }

  scope :after_cursor, ->(cursor) do
    return all if cursor.nil?

class AddSoftDeleteToDocuments < ActiveRecord::Migration[7.0]
  disable_ddl_transaction!

  def change
    add_column :documents, :marked_for_deletion_at, :datetime, null: true

-- Product.active.touch_all(:cache_synced_at) for catalog 42
UPDATE "products"
SET "updated_at" = '2024-05-01 12:00:00.123456',
    "cache_synced_at" = '2024-05-01 12:00:00.123456'
WHERE "products"."catalog_id" = 42
  AND "products"."status" = 'active';

class ExplainAnalyzer
  def initialize(relation, watched_tables:)
    @relation = relation
    @watched_tables = Array(watched_tables).map(&:to_s)
  end

class CreateTopSellersMv < ActiveRecord::Migration[7.0]
  def up
    execute <<~SQL
      CREATE MATERIALIZED VIEW top_sellers AS
        SELECT p.id            AS product_id,
               p.name          AS product_name,