Learning term
Database migration — PostgreSQL
Database migration moves schema and data reproducibly from one version to the next. This card shows its role in “PostgreSQL” and a safe diagnostic path.
Orientation
Database migration moves schema and data reproducibly from one version to the next. At this level, separate purpose, input, and visible result. Place Database migration within PostgreSQL before changing settings or files.
Practical use
Check migration state and rollback plan when application and database expect different versions. Start in a sandbox with neutral examples. Record the expected state, make one controlled change, and compare status output, application behavior, and logs.
Technical understanding
Database migration moves schema and data reproducibly from one version to the next. Technically, Database migration connects through interfaces, configuration, state, or dependencies. Trace data from input to output and check versions, permissions, networking, storage, and resources separately.
Operations and debugging
Check migration state and rollback plan when application and database expect different versions. In production-like operations, use measurable signals, least privilege, reproducible configuration, and a documented rollback. Preserve evidence, isolate the cause, and verify the correction with the same test.
Exercise
Try it safely
Check migration state and rollback plan when application and database expect different versions. Open an isolated test environment and run “psql --version && printf "%s\n" "SELECT 1;"”. Write down the expected output first, do not alter production data, and record one safe next diagnostic step.
psql --version && printf "%s\n" "SELECT 1;"Quick check
Can you explain the purpose, observable state, and most common failure source of Database migration — PostgreSQL in one sentence each? Which evidence would you preserve before changing anything, and which repeated test would prove that the correction actually worked?