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A comment on Using the expand and contract pattern for schema changes. Parent comment

Re:Using the expand and contract pattern for schema changes by evancordell on Monday November 10, 2025 @09:57AM (#45876602)
We always called these "four-phase migrations". An old Stripe article used similar naming[0].

[0]: https://stripe.com/blog/online-migrations

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Re:Using the expand and contract pattern for schema changes by sarchertech on Monday November 10, 2025 @11:59AM (#45877939)
I’ve heard that one too. I think the key insight is that you need to “stop the bleeding” (stop creating more old data that needs to be migrated) before you do any backfilling. That’s why I always called it dual writing because that’s the stop the bleeding step.
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