https://www.youngju.dev/blog 천천히 올바르게. AI Researcher & DevOps Engineer Youngju's tech blog. GPU/CUDA, LLM, MLOps, Kubernetes AI workloads, distributed training, and data engineering. ko fjvbn2003@gmail.com (Youngju Kim) fjvbn2003@gmail.com (Youngju Kim) Tue, 16 Jun 2026 00:00:00 GMT https://www.youngju.dev/blog/database/2026-06-16-expand-contract-zero-downtime-schema.en https://www.youngju.dev/blog/database/2026-06-16-expand-contract-zero-downtime-schema.en A thorough walkthrough of the Expand-Contract pattern, the standard technique for changing a live database schema without downtime. We cover per-scenario SQL for adding columns, renaming, dropping, and adding constraints, plus double-write, gradual backfill, coordinating with application code, and rollback strategy. Tue, 16 Jun 2026 00:00:00 GMT fjvbn2003@gmail.com (Youngju Kim) databasemigrationzero-downtimeexpand-contractreliability https://www.youngju.dev/blog/database/2026-06-16-expand-contract-zero-downtime-schema.ja https://www.youngju.dev/blog/database/2026-06-16-expand-contract-zero-downtime-schema.ja 稼働中のデータベースのスキーマを無停止で変更する標準手法である Expand-Contract パターンを整理します。カラム追加、リネーム、削除、制約追加といったシナリオごとの SQL と、ダブルライト、段階的バックフィル、アプリケーションコードとの連携、ロールバック戦略まで段階を追って解説します。 Tue, 16 Jun 2026 00:00:00 GMT fjvbn2003@gmail.com (Youngju Kim) databasemigrationzero-downtimeexpand-contractreliability https://www.youngju.dev/blog/database/2026-06-16-expand-contract-zero-downtime-schema https://www.youngju.dev/blog/database/2026-06-16-expand-contract-zero-downtime-schema 운영 중인 데이터베이스의 스키마를 무중단으로 바꾸는 표준 기법인 Expand-Contract 패턴을 정리합니다. 컬럼 추가, 이름 변경, 삭제, 제약 조건 추가 같은 시나리오별 SQL과 더블 라이트, 점진적 백필, 애플리케이션 코드 협업, 롤백 전략까지 단계별로 다룹니다. Tue, 16 Jun 2026 00:00:00 GMT fjvbn2003@gmail.com (Youngju Kim) databasemigrationzero-downtimeexpand-contractreliability https://www.youngju.dev/blog/database/2026-06-16-zero-downtime-data-migration-dual-write-cdc.en https://www.youngju.dev/blog/database/2026-06-16-zero-downtime-data-migration-dual-write-cdc.en Moving data to a new store without stopping the service is tricky because of consistency and ordering guarantees. This post lays out a staged cutover strategy combining Dual-Write, Backfill, and CDC, plus verification, rollback, and idempotency design from an operational point of view. Tue, 16 Jun 2026 00:00:00 GMT fjvbn2003@gmail.com (Youngju Kim) databasemigrationcdcdebeziumdual-writezero-downtime https://www.youngju.dev/blog/database/2026-06-16-zero-downtime-data-migration-dual-write-cdc.ja https://www.youngju.dev/blog/database/2026-06-16-zero-downtime-data-migration-dual-write-cdc.ja サービスを止めずにデータを新しいストアへ移すのは、一貫性と順序保証のため難しい作業です。Dual-Write、Backfill、CDC を組み合わせた段階的カットオーバー戦略と、検証、ロールバック、冪等性設計を実務の観点から整理します。 Tue, 16 Jun 2026 00:00:00 GMT fjvbn2003@gmail.com (Youngju Kim) databasemigrationcdcdebeziumdual-writezero-downtime https://www.youngju.dev/blog/database/2026-06-16-zero-downtime-data-migration-dual-write-cdc https://www.youngju.dev/blog/database/2026-06-16-zero-downtime-data-migration-dual-write-cdc 서비스를 멈추지 않고 데이터를 새 저장소로 옮기는 일은 일관성과 순서 보장 때문에 까다롭습니다. Dual-Write, Backfill, CDC를 조합한 단계별 컷오버 전략과 검증, 롤백, 멱등성 설계를 실무 관점에서 정리합니다. Tue, 16 Jun 2026 00:00:00 GMT fjvbn2003@gmail.com (Youngju Kim) databasemigrationcdcdebeziumdual-writezero-downtime