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Databases & Data

The most popular blog posts about databases & data on Hacker News. 300 posts.

2022
67

For Want of a JOIN

Once upon a time, I was on a small team tasked with building a data pipeline. On this team was someone we’ll call Bob, who was fresh out of grad school and hadn’t had much experience with software engineering, and no experience with SQL. As part of this data pipeline, Bob had to combine the data from two tables. JOIN…

72

Introduction to K-Means Clustering

Under unsupervised learning, all the objects in the same group (cluster) should be more similar to each other than to those in other clusters; data points from different clusters should be as different as possible. Clustering allows you to find and organize data into groups that have been formed organically, rather…

74

The DynamoDB Paper

This week at USENIX ATC’22, a group of my colleagues 1 from the AWS DynamoDB team are going to be presenting their paper Amazon DynamoDB: A Scalable, Predictably Performant, and Fully Managed NoSQL Database Service . This paper is a rare look at a real-world distributed system that runs at massive scale.

77

DynamoDB 10 years later

Amazon DynamoDB was introduced 10 years ago today; one of its key contributors reflects on its origins, and discusses the 'never-ending journey' to make DynamoDB more secure, more available and more performant.

80

Machine Learning Algorithms Cheat Sheet

Machine learning is a subfield of artificial intelligence (AI) and computer science that focuses on using data and algorithms to mimic the way people learn, progressively improving its accuracy. This way, Machine Learning is one of the most interesting methods in Computer Science these days, and it'

81

PostgreSQL query performance bottlenecks

PostgreSQL query planner is full of surprises, so a common-sense approach to writing performant queries is sometimes misleading. In this blog post, I'll describe examples of optimizing seemingly obvious queries with the help of EXPLAIN ANALYZE and Postgres metadata analysis.

89

PostgreSQL 14 Internals book – Part II

I’m pleased to announce that Part II of the “ PostgreSQL 14 Internals ” book is available now. This part explores the purpose and design of the buffer cache and explains the need for write-ahead logging. Please download the book freely in PDF. There are three more parts to come, so stay tuned! Thanks to Matthew Daniel…