#database

Two Transactions, One Row: What Does MySQL Actually Let You See ?

Two users, One database row, Both reading and writing at almost exactly the same time. Who sees what ?

Methods to Design Tombstones, Retention, and Cleanup Policies for Event and Audit Data

Master SQL Window Functions With Real World Examples

Stop writing SQL that just fetches data, start writing SQL that tells a story

Список рассылки Кувейта: как использовать данные для развития современного маркетинга

В условиях высокой конкуренции компаниям становится всё важнее понимать свою целевую аудиторию и строить маркетинговые кампании на основе…

I Wrote the Same 25 Million Rows 17 Ways. The Fastest Layout Was 57× Quicker Than the Slowest.

Row group size, codec, dictionary encoding and sort order, measured — plus the one-line query mistake that undoes all of it.

What Is Airtable? A Beginner’s Guide to the No-Code Database Platform

What if you could combine the simplicity of a spreadsheet with the power of a relational database — without writing code?

Dapper vs EF Core in 2026: Stop Picking a Winner, Start Picking a Boundary

Most .NET teams still treat Dapper and EF Core as opposing camps.

What It Actually Takes to Archive Billions of Financial Records Without Taking Production Down

Database archival sounds deceptively simple.

Concurrency Control in Databases: From Isolation Levels to Locking

Working with Java, Spring Boot, multithreading, and concurrency, we often deal with multiple requests being processed at the same time.

Pessimistic locking V/s Optimistic locking — Simplified

Two Developers Walk Into a Database

SQL’deki “İlişki Beyni” MongoDB’de İşe Yaramıyor — İşte Nedeni

Şu hissi bilirsiniz: Yıllarca SQL dünyasında, Entity Framework Core’un o pamuklara sarılı konfor alanında kod yazmışsınızdır. Primary…

OLTP Versus OLAP Databases

What They Are and Where You Find Them

#6: null=True on a Text Field Gives You Two Kinds of Empty

The one-word model choice that quietly splits your “empty” into "" and None — and poisons every query that touches it

Common Mistakes AI Makes When Generating SQL

AI has made writing SQL much faster.

The Foundations of Backend Engineering — Understanding Databases

The Warehouse of Your Data

Techniques to Expose Progress for Long-Running Jobs Without Polling Your Database to Death

d-lmdb: A Distributed LMDB Built on d-engine (Experimental)

Exploring how to add replication to an embedded KV (LMDB) using d-engine, with minimal changes to the read path.

OpenFDA Drug API vs Commercial Drug APIs for Healthcare Software

When comparing OpenFDA vs commercial drug APIs, the real question is not simply free versus paid. It is about data quality, workflow fit…

Adding Cost Metering and LLM Spend Visibility to a Multi-Agent System

Written by Matteo Rossi.

The Three Database Confusions That Lead Teams to Pick the Wrong Solution

Centralized vs distributed, interface vs syntax, OLAP vs HTAP — untangling concepts that derail GBase Database selection meetings.

Your Database POC Looks Good. Here’s Why It Might Still Be Useless.

A database POC can pass benchmarks and still fail in production. This guide explains three common database POC mistakes — benchmark-only…

System Requirements দেখে সঠিক Database কীভাবে বেছে নেবেন?

Software Engineer হিসেবে আমরা অনেকেই PostgreSQL, MySQL, MongoDB, Redis — এগুলোর নাম খুব সহজেই বলতে পারি।

How to Fix “MySQL Shutdown Unexpectedly” Error in XAMPP

A step-by-step guide to get your local MySQL server running again

What Is Bring Your Own Database Architecture, and Why Does It Matter for Cryptographic Security?

Most organisations running cryptographic discovery or vulnerability assessments accept a hidden trade-off: their sensitive infrastructure…

Alembic in Practice: Structure, Revisions, and the Traps SQLite Sets

What those hex filenames mean, why migrations silently applied to the wrong database for two months, and how to widen a CHECK constraint…

Database locking with raw SQL (FOR UPDATE)

Two concurrent transactions that each SELECT a row, change it in memory, then UPDATE can lose an update or claim the same resource twice…

Tips: Design Fallback Responses Without Creating Data Integrity Bugs

The Five Questions to Pick a Database: A Decision Tree for SQL, NoSQL, Cache, and Search

How to choose a database by the questions you ask your data — a decision tree that starts at Postgres and makes every exit earn its visa.

pgvector is All You Need: Replacing Expensive Vector DBs in Spring Boot

Dedicated vector databases are overpriced and introduce unnecessary network latency. Here is how to implement Retrieval-Augmented…

understanding how Django model works

Understanding how models work in Django is very crucial when building a Django application that handles data storage, retrieval and…

Database Fundamentals for Data Analysts

Types of Databases 1. Relational Database vs Non-Relational Database Relational Database A Relational Database stores data in the form of…

The API Scaled. The Database Didn’t: A Connection Budget Failure

Code: the complete Docker experiment, API, load generator, sanity test, and raw results are available in…

Database Migrations Done Right: Flyway vs Liquibase in Spring Boot

Your application code lives in Git. Every change is reviewed, versioned, and reproducible. You can check out any commit and rebuild the…

PostgreSQL 學習筆記：認識資料庫索引與 EXPLAIN ANALYZE

本篇為六角學院2026年node.js直播班中，關於資料庫索引的學習筆記整理，課中使用的資料庫為PostgreSQL，筆記內容來自課程、PostgreSQL官方文件整合而來。

Methods to Roll Out Breaking Database Changes Without a Freeze Window

#1: Django’s .update() Skips Your save() and Nobody Warns You

The one-line ORM call that changes your database but silently ignores your signals, validation, and timestamps

How Database Indexes Actually Work — Part 2: Using Them in the Real World

…knowing how an index works is not the same as knowing when to use one. This part is about that second skill: the judgment.

How Database Indexes Actually Work — Part 1: The Engine Inside

…the same query can take 5 milliseconds or 5 seconds. You did not change a single line of SQL. The only difference is INDEX…

Be Careful Where You Place Your Database

It Is the Center of Everything You Do

Why Two Drivers Accepted the Same Ride (and the Tiny Database Trick That Prevents It)

Part 2 of building a ride hailing app like Uber

Data Post 27: Revisit Mary’s IT Application — The Full Circle Moment

It has been a while since we checked in on Sally and Mary.

Business To Consumer Marketing Database for Coordinated Direct Marketing

One Audience Foundation Across Several Channels

The Most Expensive Line of Python Code Is Often the One Nobody Notices

The Outbox Pattern, Explained by a Real Problem (Without Breaking the App)

The obvious solution is a database transaction. Here’s why that breaks across two databases, and what I did instead.

How Database IndexingActually Works

A beginner’s journey from “CREATE INDEX” to understanding pages, slots, and B-trees.

After 3 Years and 200M Rows, I Finally Stopped Using UUIDs as Primary Keys

The alert hit my phone while I was mid bite into a sandwich, and my first thought was that someone had restarted the wrong service again.

How ClickHouse Stores and Finds Data So Fast — Explained for SQL Users

I’ve spent the last few months building on top of ClickHouse, and the thing that hooked me wasn’t a benchmark chart. It was a moment of…

TimescaleDB: The Complete Guide — Part 2 : High Availability

Data Ingestion, Time-Series Queries, Continuous Aggregates, Compression, Retention Policies, and High Availability

mmap behind the scenes in a database

I have spent the last three years building databases. Two of them actually, both append only, both storing data at TB scale. The first one…

Graph Data Modelling: A Functional Framework for Getting It Right

Using Oil & Gas subsurface data as a real-world case study