Tostino

Making Postgres materialized view refreshes O(delta) instead of O(total)

Many developers assume PostgreSQL materialized views handle incremental updates out of the box. They do not. If you have a materialized view with millions of rows and a single underlying record changes, both native refresh options process the entire dataset.

Because of this limitation, anyone needing immediate maintenance or working with large datasets must abandon materialized views entirely. The standard workaround is to manually maintain a standard table using custom database triggers or application logic.

I've been working on a patch to fix this. It adds an optional WHERE clause to the REFRESH MATERIALIZED VIEW command, letting you scope a refresh to exactly the rows that changed. The patch is currently under review on the pgsql-hackers mailing list.

This approach requires two things. First, the materialized view must have a unique index (the same requirement as REFRESH MATERIALIZED VIEW ... CONCURRENTLY). Second, the

jameskerr

import Base from "controllers/base";

export default class extends Base {
  static targets = ["checkbox", "toggler", "count", "menu", "hide"];

  mount() {
    this.on("turbo:morph", document, this.update);
    this.on("click", this.togglerTarget, this.toggle);
  }

kyrylo

# frozen_string_literal: true

class ApplicationService
  def self.call(...)
    new(...).call
  end

  def initialize(...)
  end
end

mjankowski

# frozen_string_literal: true

# RE: https://github.com/rails/rails/issues/50776#issuecomment-2148033957

require "bundler/inline"

gemfile(true) do
  source "https://rubygems.org"

  gem "rails", "7.1.3.3"

dhh

/*
  ERB template chunk from The Feed's display of emails:

  <section class="postings postings--feed-style" id="postings"
      data-controller="pagination" data-pagination-root-margin-value="40px">
    <%= render partial: "postings/snippet", collection: @page.records, as: :posting, cached: true %>

    <%= link_to(spinner_tag, url_for(page: @page.next_param),
          class: "pagination-link", data: { pagination_target: "nextPageLink", preload: @page.first? }) unless @page.last? %>
  </section>

empijei

package csrf

import "errors"

// This is just an example on how to reduce redundant code in Go
// Original file: https://github.com/gofiber/csrf/blob/dde96da6711a2cc01709a66730c2e16328b22047/main.go

// csrfFromExtractor returns a function can be used to bind to a parameter name to extract a csrf token from a Ctx.
func csrfFromExtractor(errMessage string, extractor func(c *fiber.Ctx, param string) string) func(string) func(c *fiber.Ctx) (string, error) {
	return func(param string) func(c *fiber.Ctx) (string, error) {

ProGM

Arel Cheatsheet on Steroids

A (more) complete cheatsheet for Arel, including NamedFunction functions, raw SQL and window functions.

Tables

posts = Arel::Table.new(:posts)
posts = Post.arel_table # ActiveRecord

Table alias

rushilgupta

INTRO

Concurrency is a domain I have wanted to explore for a long time because the locks and the race conditions have always intimidated me. I recall somebody suggesting concurrency patterns in golang because they said "you share the data and not the variables".

Amused by that, I searched for "concurrency in golang" and bumped into this awesome slide by Rob Pike: https://talks.golang.org/2012/waza.slide#1 which does a great job of explaining channels, concurrency patterns and a mini-architecture of load-balancer (also explains the above one-liner).

Let's dig in:

Goroutines

bastman

Docker - How to cleanup (unused) resources

Once in a while, you may need to cleanup resources (containers, volumes, images, networks) ...

delete volumes

// see: https://github.com/chadoe/docker-cleanup-volumes

$ docker volume rm $(docker volume ls -qf dangling=true)

$ docker volume ls -qf dangling=true | xargs -r docker volume rm

dhh

# Original Rails controller and action
class EmployeesController < ApplicationController
  def create
    @employee = Employee.new(employee_params)
    
    if @employee.save
      redirect_to @employee, notice: "Employee #{@employee.name} created"
    else
      render :new
    end