Random thoughts on concurrency, databases and distributed systems

Andrei Pechkurov

Andrei Pechkurov

289 followers

Core database engineer at QuestDB. Distributed systems gazer. Node.js contributor. Occasional tech blogger and speaker.

Seqlock-Based Atomic Memory Snapshots

Aug 6, 2023

Last time we discussed k-word CAS algorithm and came to the conclusion that seqlock-based atomic snapshots may be used as an alternative in situations...

Seqlock-Based Atomic Memory Snapshots

A Few Thoughts on K-Word CAS

Jul 6, 2023

A few months ago I went through Efficient Multi-word Compare and Swap paper, so here are a few thoughts on the algorithm. Long story short, I have...

A Few Thoughts on K-Word CAS

The Secret Life of fsync

Mar 31, 2023

Several times I've heard opinions that many mass-market SSDs and HDDs don't provide sufficient durability guarantees and Linux can do nothing with...

The Secret Life of fsync

Multithreaded Scatter-Gather Execution Model for Analytical Queries

Jan 14, 2023

Today we'll be discussing an approach used in some analytical databases to speed up the execution of queries at the cost of additional HW resources,...

Multithreaded Scatter-Gather Execution Model for Analytical Queries

BuzzwordBusters: What Does Lock-Free, Wait-Free Really Mean?

Dec 18, 2022

It seems to be a common belief that code which uses mutexes/locks/synchronized methods is "slow" and, as soon as you replace them with atomics, your...

BuzzwordBusters: What Does Lock-Free, Wait-Free Really Mean?

Concurrent Map in Go vs Java: Yet Another Meaningless Benchmark

Nov 4, 2022

Today we're comparing Java's j.u.c.ConcurrentHashMap and Go's xsync.MapOf in a totally non-scientific, unfair benchmark. While most of such language...

Concurrent Map in Go vs Java: Yet Another Meaningless Benchmark