aggregation

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

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

-- ROW_NUMBER: Unique sequential number
SELECT
  name,
  department,
  salary,
  ROW_NUMBER() OVER (ORDER BY salary DESC) as overall_rank,

@Component
public class SalesRollupScheduler {

    private static final Logger log = LoggerFactory.getLogger(SalesRollupScheduler.class);
    private static final int ROLLUP_WINDOW_DAYS = 3;

use std::collections::VecDeque;

pub struct RollingAverage {
    buf: VecDeque<f64>,
    capacity: usize,
    sum: f64,

CREATE TABLE daily_metrics (
    id          BIGGENERATED ALWAYS AS IDENTITY PRIMARY KEY,
    tenant_id   BIGINT      NOT NULL,
    metric      TEXT        NOT NULL,
    day         DATE        NOT NULL,
    count       BIGINT      NOT NULL DEFAULT 0,

@Configuration
@EnableAsync
public class AsyncConfig {

    @Bean(name = "downstreamExecutor")
    public ThreadPoolTaskExecutor downstreamExecutor() {

from django.db import models
from django.db.models import Avg, Count, Sum, DecimalField
from django.db.models.functions import Coalesce, TruncDate
from django.utils import timezone

package metrics

import "time"

type bucket struct {
	start time.Time

<?php

use Illuminate\Database\Migrations\Migration;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Support\Facades\Schema;

import { Knex } from 'knex';

export interface RawDailyRow {
  day: string;
  order_count: string;
  gross_cents: string;

use chrono::NaiveDate;
use rust_decimal::Decimal;
use serde::{Deserialize, Deserializer};

#[derive(Debug, Clone, Deserialize)]
pub struct Transaction {

<?php

use Illuminate\Database\Migrations\Migration;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Support\Facades\Schema;