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Database Concepts ​

The database is the system's shared, persistent state. Application code is replaced on every deploy, while the data and its schema stay. These concepts cover working with that shared state safely under continuous deployment.

Database Topics ​

Database Safety Under Continuous Deployment ​

When every merge reaches production within minutes, each database decision goes live against real data and load with no human review of the running result. This article covers four disciplines that keep the database safe under those conditions.

You'll Learn:

  • Why schema changes are backward compatible with the running application, and how expand and contract makes incompatible changes safe
  • What query review can see at the pull request, and what only the running database can answer
  • The data modeling choices that hold up as a table grows
  • How modules compose data across boundaries without a shared-table join