Category Archives: Без рубрики

Here are battle-tested naming practices that reduce conflicts, improve reviews, and make rollbacks/audits sane. Goals of a good changeset name A changeset identity in Liquibase is effectively:(id + author + file path) So good naming must: be unique be stable … Continue reading →

In Liquibase, you roll back only the last executed changeset using a count-based rollback. The direct answer (what interviewers want) This rolls back exactly the most recently applied changeset, using its explicit rollback definition (if present). How this actually works … Continue reading →

updateSQL is a Liquibase “dry-run” command that shows you the exact SQL Liquibase would execute, without actually changing the database. One-sentence definition (interview-ready) updateSQL generates the SQL statements for pending changesets so you can review or approve them before execution. … Continue reading →

You split large Liquibase changelogs by composition, not chronology: one master changelog that includes many small, purpose-focused changelogs. Core idea (interview-ready) Use a single master changelog that includes modular changelogs by domain, feature, or layer, keeping each file small and … Continue reading →

Short answer: there’s no functional difference — only readability, verbosity, and team preference.Liquibase treats YAML and XML identically after parsing. Core truth (interview-ready) YAML and XML changelogs express the same Liquibase model; the difference is syntax, not capability. Side-by-side comparison … Continue reading →

Preconditions make a changelog defensive: they verify assumptions about the database before a changeset runs, preventing unsafe or invalid migrations. One-sentence definition (interview-ready) Preconditions are checks evaluated before a changeset executes that ensure the database is in the expected state, … Continue reading →

Labels in Liquibase are a filtering mechanism that lets you group changesets by purpose and selectively run them, independent of environment. One-sentence definition (interview-ready) Labels are logical tags on Liquibase changesets that let you include or exclude migrations based on … Continue reading →

Contexts are a Liquibase feature that lets you control which changesets run in which environment or situation. One-sentence definition (interview-ready) Contexts are tags on Liquibase changesets that determine whether a change runs based on the active environment (dev, test, prod, … Continue reading →

The short, correct definition (interview-ready) VACUUM removes dead tuples created by updates/deletes so PostgreSQL can reuse space and keep queries fast. Why VACUUM exists (MVCC in 30 seconds) Postgres uses MVCC: UPDATE doesn’t overwrite a row → it creates a … Continue reading →

application.yml DataSource + Liquibase beans (Java) Folder structure example: Why disable spring.liquibase.enabled? Spring Boot’s default Liquibase auto-config assumes one datasource. With multiple DBs, you want explicit control so: each changelog targets the right DB failures are obvious no accidental migrations … Continue reading →