March 2025
Intermediate to advanced
202 pages
4h 45m
English
Content preview from Real-World Event Sourcing
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Evolving Event Schemas
The evolution of events is often one of the most difficult and misunderstood aspects of maintaining event-sourced systems, so let’s start there. The most important thing to remember for this section and throughout the rest of this chapter is another law of event sourcing: “Event Schemas Are Immutable.”
Event Schemas Are Immutable | |
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Event schemas must never change. Any change to an event schema produces a brand-new event type. This means that each newversion of an event is a unique type. |
This law may seem a bit inflexible, so let’s explore the reasoning behind it with some examples. Imagine that you’ve created an application ...
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.