Database Migration — Full HD

Early attempts to move often look like a "Big Bang" approach. You turn off the application, copy the database, and turn it on in the new location.

Here is the story of how that migration happens, from disaster to triumph. Chapter 1: The Disastrous "Big Bang" (What Not to Do) database migration

A dedicated "tiger team" tests every byte to ensure data integrity. Chapter 3: The Darkest Hour (When Things Go Wrong) Early attempts to move often look like a "Big Bang" approach

Smart companies choose a phased migration. They use to replicate data incrementally from the old house to the new one while people are still living in the old one. Chapter 1: The Disastrous "Big Bang" (What Not

The application is updated to write data to both the old and new databases simultaneously. This keeps the new system "warm" and up-to-date.

For a high-traffic app, "turning it off" for 4 hours costs millions in revenue and causes massive customer anger.

Despite the best planning, migrations are "10x more difficult than people think".