はじめに 「論理削除？deleted_atカラム追加すればいいでしょ」この一言から始まる地獄を、何度見てきただろうか。 最初は簡単に見える。カラムを1つ追加するだけ。しかし、その「簡単さ」こそが罠だ。 論理削除は技術的負債の温床だ。WHERE句への条件追加忘れ、認知コストの増大、テストの複雑化、パフォーマンス劣化。すべては「最初にドメインを考えなかった」ツケである。 しかし現実として、サービスを運用していくと論理削除が必要になる場面は確実に訪れる。 論理削除の本質は、「このレコードは存在するが、存在しないことにしてほしい」という矛盾だ。この矛盾を解消するか、受け入れて安全に管理するか。本記事ではその両方のアプローチを解説する。 なお、私はDBのスペシャリストではないので、ここで紹介する方法が唯一の正解というわけではない。あくまで一つのアプローチとして参考にしてほしい。データベース設計は文脈
防衛省サイバーコンテスト 2025 writeup - st98 の日記帳 - コピー
2/2に12時間というちょうどよい競技時間で開催された。21時終了だったけれども、11時45分ぐらいに最速で全完して1位🎉 第1回以来4年ぶりの優勝だ。昨年大会の第4回ではヒントの閲覧数で優勝を逃してしまって悔しい思いをしたので、雪辱を果たすことができ嬉しい。開始直後からずっと1位を独走できており、510名のプレイヤーがいる中で圧勝だったのも嬉しい。 昨年度や一昨年度はバルクが作問を担当していたが、今回はAGESTが担当していた。これまでの問題と比較すると全体的に易化したように思うが、解くにあたって発想の大きな飛躍を必要とするいわゆる「エスパー要素」のある問題はごく一部を除いて存在しておらず*1、よかったと思う。また、昨年度・一昨年度に引き続きwriteupは公開可能というのもよかった。 戦略というほどの戦略は立てていなかったけれども、とりあえずWebを見た後は全カテゴリを上から見ていき
タイミーで蓄積された Aurora MySQL 運用ナレッジ─ 障害・チューニング・実践知を特別公開 - Timee Product Team Blog
はじめに タイミーで SRE 業務を担当している徳富（@yannKazu1）です。 日々、数千万件のデータと向き合う中で、Aurora MySQL の運用をより良くするための改善を積み重ねています。 本記事では、その中で経験してきた “机上ではわからないリアルな気づきや学び” を、できるだけ具体的にまとめました。 これから Aurora を本気で運用したい方や、同じような課題に悩んでいる方のヒントになれば嬉しいです。 (この記事はTimee Product Advent Calendar 2025の3日目の記事です。) 1. オンラインDDLでも「ゼロロック」ではない ─ ALTER TABLE 実行時の落とし穴 「MySQL のオンラインDDLなら、日中でもサッと ALTER できるよね？」 ──そんなふうに思ってしまうこと、ありますよね。 たしかにオンラインDDLはとても便利で、データ
Consider SQLite
If you were creating a web app from scratch today, what database would you use? Probably the most frequent answer I see to this is Postgres, although there are a wide range of common answers: MySQL, MariaDB, Microsoft SQL Server, MongoDB, etc. Today I want you to consider: what if SQLite would do just fine? For those who are unfamiliar, SQLite is a implementation of SQL as a library — this means t
TinyBase
(Baffled by all these logos? Check out our architectural options guide to make sense of it all!) Start with a simple key-value store.Creating a Store requires just a simple call to the createStore function. Once you have one, you can easily set Values in it by unique Id. And of course you can easily get them back out again. Read more about using keyed value data in The Basics guide. import {create
Today, we are excited to announce the launch of .NET 10, the most productive, modern, secure, intelligent, and performant release of .NET yet. It’s the result of another year of effort from thousands of developers around the world. This release includes thousands of performance, security, and functional improvements across the entire .NET stack-from languages and developer tools to workloads-enabl
OWASP ZAP の finding を Rust/Axum の handler に戻して直す - じゃあ、おうちで学べる
はじめに vulnerable-app に ZAP の full scan を回すと、High finding が並びます。XSS、SQL Injection、Path Traversal。alert 名を眺めて、ふと気づく。これは「危険です」の一覧ではない。handler への差し戻し指示書だ。 OWASP ZAP を実行すると、HTML、Markdown、JSON のレポートが出ます。そこには Cross Site Scripting (Reflected)、SQL Injection、Path Traversal のような名前が並びます。ただ、alert 名だけを見ても修正は始まりません。必要なのは、finding を実際の handler、SQL、HTML 出力、ヘッダ設定に戻すことです。 OWASP ZAP は OSS の web 脆弱性スキャナで、HTTP リクエストを投げて挙
The Fediverse has been a hot topic of discussion lately, with thousands, if not millions, of new users creating accounts on platforms like Mastodon to either move entirely to "the other side" or experiment and learn about this new social network. Today we're introducing Wildebeest, an open-source, easy-to-deploy ActivityPub and Mastodon-compatible server built entirely on top of Cloudflare's Super
缶つぶし機とソフトウェア移行技術 - Refactoring to Rust の読書感想文 - じゃあ、おうちで学べる
はじめに ——あるいは、「知っている」と「理解している」の間 Rustのことは、知っていた。学習もしていた。実務でも使っていた。 でも、それは知っているつもりだった。 知ってるつもり 無知の科学 (ハヤカワ文庫NF) 作者:スティーブン スローマン,フィリップ ファーンバック早川書房Amazon 日々Rustで開発し、BoxとRcとArcを使い分け、tokio::spawnでタスクを生成し、?演算子を当たり前のように書いている。FFI？PyO3使えばいいでしょ。WebAssembly？wasm-bindgenがあるじゃない。技術的には、確かに「使える」レベルにはあった。 でも、心のどこかで感じていた違和感があった。 オートバイのエンジンを分解できる人と、エンジンが動く原理を理解している人は違う。コードが動くことと、なぜそう書くべきかを理解することも違う。私は前者だった。メカニックではあった
【PGlite】WebAssemblyでPostgreSQLを軽量に - RAKUS Developers Blog | ラクス エンジニアブログ
はじめに PGliteの概要 PGliteの特徴 PGliteを試す ブラウザで使う PGliteの速度計測 まとめ はじめに こんにちは！エンジニア２年目のTKDSです！ 今回はPGliteについて調べてみました！ 概要・使い方・速度実験・まとめの内容で記事は構成されています。 使ってみた結果として、軽量高速であり色々使いみちがありそうなツールだと感じました。 ぜひ最後まで読んでいただけると幸いです。 PGliteの概要 PGliteは、PostgreSQLをWebAssembly（WASM）にコンパイルした軽量なデータベースエンジンです。 これにより、ブラウザ、Node.js、Bun、DenoなどでPostgreSQLの機能を利用でき、開発者はローカルやサーバーレス環境でデータベース操作を行うことが可能です。 PGliteは、インメモリデータベースやファイルシステム（Node.jsやB
We’re not going to bury the lede: we’re excited to launch a major update to our D1 database, with dramatic improvements to performance and scalability. Alpha users (which includes any Workers user) can create new databases using the new storage backend right now with the following command: $ wrangler d1 create your-database --experimental-backend In the coming weeks, it’ll be the default experienc
OpenAI scales PostgreSQL to support millions of QPS across critical services using an unsharded architecture with one primary and dozens of replicas on Azure. They tackle write bottlenecks and MVCC challenges like bloat and replication lag by offloading writes, optimizing queries, carefully managing schema changes, and dedicating replicas for high-priority reads. This approach has enabled signific
The product https://joinmastodon.org Mastodon is a free, open-source social network server based on ActivityPub where users can follow friends and discover new ones. On Mastodon, users can publish anything they want: links, pictures, text, and video. All Mastodon servers are interoperable as a federated network. Open source The project is open source at https://github.com/mastodon/mastodon License
Hatchet
Over the past half year or so, I’ve been writing an internal doc for our engineers trying to distill two years of Postgres battles into a somewhat cohesive document. While I love the Postgres manual, I find it’s hard to turn to when shit hits the fan because it’s just so darn comprehensive. I thought this might be useful for others and would appreciate feedback (or other tidbits that you’ve learne
There is a pattern I am very fond of - “one database per tenant” in web applications with multiple, isolated users. Recently, I needed to fix an application I had for a long time where this database-per-tenant multitenancy utterly broke down, because I was doing connection management wrong. Which begat the question: how do you even approach doing it right? And it turns out I was not alone in this.
Builder Day 2024: 18 big updates to the Workers platform
Try out Workers Logs today. You can learn more from our developer documentation, and give us feedback directly in the #workers-observability channel on Discord. Connect to private databases from WorkersStarting today, you can now use Hyperdrive, Cloudflare Tunnels and Access together to securely connect to databases that are isolated in a private network. Hyperdrive enables you to build on Workers
Building data-centric apps with a reactive relational database
Building apps is too hard. Even skilled programmers who don’t specialize in app development struggle to build simple interactive tools. We think that a lot of what makes app development hard is managing state: reacting and propagating changes as the user takes actions. We’re exploring a new way to manage data in apps by storing all app state—including the state of the UI—in a single reactive datab
By Jun He, Natallia Dzenisenka, Praneeth Yenugutala, Yingyi Zhang, and Anjali Norwood TL;DRWe are thrilled to announce that the Maestro source code is now open to the public! Please visit the Maestro GitHub repository to get started. If you find it useful, please give us a star. What is MaestroMaestro is a horizontally scalable workflow orchestrator designed to manage large-scale Data/ML workflows
Local-first software: You own your data, in spite of the cloud
Cloud apps like Google Docs and Trello are popular because they enable real-time collaboration with colleagues, and they make it easy for us to access our work from all of our devices. However, by centralizing data storage on servers, cloud apps also take away ownership and agency from users. If a service shuts down, the software stops functioning, and data created with that software is lost. In t
Adopting Wide Event-style instrumentation has been one of the highest-leverage changes I've made in my engineering career. The feedback loop on all my changes tightened and debugging systems became so much easier. Systems that were scary to work on suddenly seemed a lot more manageable. Lately there have been a lot of good blog posts on what "Wide Events" mean and why they are important. Here are
New AWS Security Agent secures applications proactively from design to deployment (preview) | Amazon Web Services
AWS News Blog New AWS Security Agent secures applications proactively from design to deployment (preview) Updated on March 31, 2026 – AWS Security Agent on-demand penetration testing is now generally available. New customers can explore AWS Security Agent with a 2-month free trial. — Today, we’re announcing AWS Security Agent in preview, a frontier agent that proactively secures your applications
I see a lot of bad system design advice. One classic is the LinkedIn-optimized “bet you never heard of queues” style of post, presumably aimed at people who are new to the industry. Another is the Twitter-optimized “you’re a terrible engineer if you ever store booleans in a database” clever trick1. Even good system design advice can be kind of bad. I love Designing Data-Intensive Applications, but
Google I/O 2024 is here, and just like in previous years, we have many new products and features to tell you about. But first, a look back. For years, millions of you developers have been using Firebase to accelerate your app development and run your apps with confidence. From Realtime Database to Remote Config, we’ve been obsessed with helping you speed up and simplify your work so that you can m
Database Fundamentals
About a year ago, I tried thinking which database I should choose for my next project, and came to the realization that I don't really know the differences of databases enough. I went to different database websites and saw mostly marketing and words I don't understand. This is when I decided to read the excellent books Database Internals by Alex Petrov and Designing Data-Intensive Applications by
Aurora PostgreSQLでテーブルパーティショニングを導入した話 【実践編】 - GO Tech Blog
技術戦略部 SREグループの古越です。 前回の記事でパーティショニングを導入する段階で注意するポイントについて主に触れてきました。今回は導入するために具体的に行った事や追加で導入する拡張機能の解説などを踏まえて紹介していきます。 前提知識と導入するまでの背景については前回の検討編を見て頂ければと思います。 Aurora PostgreSQLでテーブルパーティショニングを導入した話 【検討編】 実践したこと 前回のブログでも軽く触れましたが、導入する前には以下を重点的に検証し、実践しました。 パーティション管理の自動化のため pg_partmanを導入する local開発環境でpg_partmanを利用可能にする Aurora PostgreSQLパラメーターのチューニング パーティションの一部をS3にエクスポートする このあたりを具体的に解説していければと思います。 1. pg_partm
アプリケーションを構築する場合にはデータを保存するため必ずデータベースが必要となります。データベースを効率的に管理し、簡単に操作を行うためのツールがPrismaです。本文書はこれまでPrismaを利用したことがない人を対象にPrismaを利用する上での基本的な操作と設定方法について説明を行なっています。 Prismaはサーバからデータベースを操作する際にサーバとデータベースの間を仲介する役目を持っておりデータベースを操作する際はどのデータベースを利用しているか意識することなく共通のオブジェクトメソッドを利用することができます。本文書ではサーバにExpress.jsを利用して最初はデータベースのSQLiteを利用します。SQLiteで一通り動作を確認した後にクラウドサービスのSupabase(PostgreSQL)に変更します。データベースの変更を行なってもSQLiteで行なった処理と同じ操
I am starting this new year the same way I ended the last: taking antibiotics because my biological daughter brought home a nasty sinus bug from Carnegie Mellon’s preschool. This was after my first wife betrayed me and gave me COVID. Nevertheless, it is time for my annual screed on last year’s major database happenings and trends since a lot has happened. My goal is to keep my trenchant opinions f
The WebAssembly (Wasm) ecosystem is transforming. Developers can look forward to a modular, virtualizable, and robust environment for building applications, libraries, and services. We are excited to be working towards this with implementations for WASI-Preview 2. This roadmap reflects changes occurring in standards within the WebAssembly Community Group (CG) and the WASI Subgroup within the W3C.
Concurrency is not very intuitive. You need to train your brain to consider what happens when multiple processes execute a certain code block at the same time. There are several issues I often encounter: Failing to recognize potential concurrency issues: It's not uncommon for both beginner and seasoned developers to completely miss a potential concurrency problem. When this happens, and the concur
Why DuckDB
There are many database management systems (DBMS) out there. But there is no one-size-fits-all database system. All take different trade-offs to better adjust to specific use cases. DuckDB is no different. Here, we try to explain what goals DuckDB has and why and how we try to achieve those goals through technical means. To start with, DuckDB is a relational (table-oriented) DBMS that supports the
Horizontally scaling the Rails backend of Shop app with Vitess - Shopify
Horizontally scaling the Rails backend of Shop app with VitessShop app horizontally scaled a Ruby on Rails app with Vitess. This blog describes Vitess and our detailed approach for introducing Vitess to a Rails app. Good problems We experienced hockey stick growth after we launched the Shop app. We were glued to our dashboards and saw millions of users onboard onto the app. This was gratifying, bu
Introducing Apache Arrow Flight SQL: Accelerating Database Access
Introducing Apache Arrow Flight SQL: Accelerating Database Access Published 16 Feb 2022 By José Almeida, James Duong, Vinicius Fraga, Juscelino Junior, David Li, Kyle Porter, Rafael Telles We would like to introduce Flight SQL, a new client-server protocol developed by the Apache Arrow community for interacting with SQL databases that makes use of the Arrow in-memory columnar format and the Flight
週刊Railsウォッチ: Rack 3アップグレードガイド、Stimpack gemほか（20220926前編）｜TechRacho by BPS株式会社
週刊Railsウォッチについて 各記事冒頭には🔗でパーマリンクを置いてあります: 社内やTwitterでの議論などにどうぞ 「つっつきボイス」はRailsウォッチ公開前ドラフトを（鍋のように）社内有志でつっついたときの会話の再構成です👄 お気づきの点がありましたら@hachi8833までメンションをいただければ確認・対応いたします🙏 TechRachoではRubyやRailsなどの最新情報記事を平日に公開しています。TechRacho記事をいち早くお読みになりたい方はTwitterにて@techrachoのフォローをお願いします。また、タグやカテゴリごとにRSSフィードを購読することもできます（例:週刊Railsウォッチタグ） 🔗Rails: 先週の改修（Rails公式ニュースより） 公式更新情報: Ruby on Rails — Bugfixes, improvements an
Web scraping is the process of downloading data from a public website. For example, you could scrape ESPN for stats of baseball players and build a model to predict a team’s odds of winning based on their players stats and win rates. Below are a few use-cases for web scraping. Monitoring the prices of your competitors for price matching (competitive pricing). Collecting statistics from various web
The In-depth Guide to ActiveRecord load_async in Rails 7 Updated Mar 1, 2022 17 minute read Rails 7 introduces ActiveRecord load_async method that runs SQL queries asynchronously in the background thread. This seemingly simple change of just adding a single new method that takes no arguments has profound implications for database layer interactions. In this tutorial, we’ll deep dive into the intri
Hello! I'm kicking off another article series about the internals of PostgreSQL. This one will focus on query planning and execution mechanics. This series will cover: Query execution stages (this article) Statistics Sequential scan Index scan Nested-loop join Hash join Merge join This article borrows from our course QPT Query Optimization (available in English soon), but focuses mostly on the int
The challenges of supporting foreign key constraints — PlanetScale
PlanetScale Postgres is the fastest way to run Postgres in the cloud. Plans start at just $5 per month. Learn more By Shlomi Noach, Manan Gupta | December 5, 2023 Today, PlanetScale announced support for foreign key constraints. This has been in the making for quite a while — around a year in fact. So, what was the problem? Why did it take so long? It's something that any and every database suppor
[Twitter discussion, LinkedIn] Updates Jan 3, 2023: Update the online features section to differentiate between real-time features and near real-time features. If you’re interested in this topic, my book Designing Machine Learning Systems (O’Reilly, June 2022) covers online prediction and continual learning in much more detail. Real-time machine learning is the approach of using real-time data to
Hacking Google with A.I. for $500,000What happens when you unleash an AI across all of Google's infrastructure? 1,500 APIs, 3,600 keys, and $500,000 in bounties later, here's what I found. After being invited to bugSWAT Mexico in October 2025, I found myself drawn back to Google research. While I'd been focused on other projects for several months, the team's willingness to give researchers a peek
crawshaw - 2025-06-08
How I program with Agents 2025-06-08 This is the second part of my ongoing self-education in how to adapt my programming experience to a world with computers that talk. The first part, How I program with LLMs, covered ways LLMs can be adapted into our existing tools (basically, autocomplete) and how careful prompting can replace traditional web search. Now I want to talk about the harder, and more
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論理削除という技術的負債、それでも僕たちは使い続ける - じゃあ、おうちで学べる
Announcing .NET 10 - .NET Blog
Welcome to Wildebeest: the Fediverse on Cloudflare
D1: We turned it up to 11
OpenAI: Scaling PostgreSQL to the Next Level
Mastodon: Ruby on Rails Open Source Web App
A can of shardines: SQLite multitenancy with Rails
Maestro: Netflix’s Workflow Orchestrator
A Practitioner's Guide to Wide Events | Jeremy Morrell
Everything I know about good system design
What's new in Firebase at I/O 2024
Node.js(Express.js)環境でPrisma ORMを使いこなすための基礎 | アールエフェクト
Databases in 2023: A Year in Review
WebAssembly: An Updated Roadmap for Developers
Handling Concurrency Without Locks
How to Crawl the Web with Scrapy
In-depth Guide to ActiveRecord load_async in Rails 7
Queries in PostgreSQL. Query execution stages
Real-time machine learning: challenges and solutions
Hacking Google with A.I. for $500,000