Category Archives: Без рубрики

By default, Flyway fails migration when it detects a version gap, because it assumes a migration is missing. 📌 One-liner: “A version gap is treated as a missing migration and causes validation to fail.” What Flyway considers a “version gap” … Continue reading →

Placeholders in Flyway are variables that let you parameterize SQL migrations so the same script can run in different environments with different values. 📌 One-liner: “Placeholders let you write one migration and inject environment-specific values at runtime.” How placeholders work … Continue reading →

Flyway integrates with Maven and Gradle via official plugins that expose Flyway commands as build goals/tasks (migrate, validate, info, baseline, repair, clean), and by letting you configure Flyway the same way you would in app runtime: URL/user/password, locations, schemas, placeholders, … Continue reading →

Short definition (what you say first) A Flyway baseline marks an existing database schema as a starting point so Flyway can begin managing migrations without reapplying old ones. 📌 One-liner: “Baseline tells Flyway: assume the schema up to this version … Continue reading →

Short answer (what you say first) Java-based migrations allow you to implement migrations that are too complex, conditional, or data-driven for plain SQL, while still being versioned and transactional under Flyway control. 📌 Interview one-liner: “They’re for logic-heavy or DB-aware … Continue reading →

What are Flyway callbacks? Callbacks are hooks that Flyway executes at specific points of the migration lifecycle. They let you run custom logic: before / after migrations before validation after repair on success / on error 📌 Key idea: “Callbacks … Continue reading →

Flyway detects checksum mismatches during validation and fails migration to prevent schema drift.A mismatch means an already-applied migration file was changed. Key phrase: “Checksum mismatches indicate a violation of migration immutability.” How Flyway detects a checksum mismatch Flyway stores, for … Continue reading →

validateOnMigrate tells Flyway to validate applied migrations against the local migration files before running migrate.If validation fails → migration stops. 📌 One-liner: “It ensures the database history matches the migration files before applying new migrations.” What “validation” actually checks When … Continue reading →

Short definition (what interviewers expect first) flyway.repair() is a maintenance command that fixes Flyway’s metadata table (flyway_schema_history) so migrations can proceed safely again.It does not change the database schema — it only repairs Flyway’s internal state. 📌 Key phrase: “Repair … Continue reading →

What is a repeatable migration in Flyway? In Flyway, a repeatable migration is a migration that: Has no version number Can be re-executed automatically Is identified by a checksum, not a version Filename format: Example: How Flyway decides when to … Continue reading →