r/databasedevelopment

I Tried To Decode Postgres WAL for an INSERT Statement

Hi everyone,

This is a continuation of the explorations from my previous posts here. I went through the CMU Database Systems course, and I'm exploring topics around databases. I wanted to see how the Write Ahead Log is constructed and logged. So I tried to trace a WAL record for a simple INSERT statement in Postgres.

I recorded a video walkthrough of the terminal and source code exploration here: https://youtu.be/YOyq-kvbyU8?si=PTdexP3jmOSdx-8y

I've tried to explore how we can locate a WAL record, how we can decode it via either xxd or pg_waldump, and the relevant source code for it. Do give a watch and consider supporting :)

This is partly for my own future reference and partly to share with others who might be interested in it. Would love feedback and corrections from people who know this stuff deeply. Apologies if this isn't the correct subreddit for this.

Thank you so much!

u/IndicationAntique667 — 11 days ago

▲ 11 r/databasedevelopment

MECHLOVE Blueprint - 1/7. General: Pretty Much Classical RDBMS at Heart, with Each and Every Component Redesigned

We are writing yet another RDBMS, and would appreciate any feedback on our blueprints; while the RDBMS is classical at heart (with WAL and data pages and fuzzy checkpoints), each and every component underneath was redesigned - from WAL being non-ARIES and ZFS-style on-disk CoW to in-memory CoW and cache- and SIMD-friendly page layouts. Our philosophy is playing alongside modern hardware instead of fighting it, MECHLOVE being the highest form of Mechanical Sympathy. As a result, we hope it will beat Hekaton (while being mostly open-source except for certain enterprise features such as HA and at-rest encryption).

Please feel free to comment.

6it.dev

u/no-bugs — 13 days ago