https://hashitosystem.com/en/blog/uuid-v7-time-ordered-keys/ Hashito System Tech Blog en 2026-07-31 UUID v7 and Time-Ordered Keys: Benefits and Pitfalls as a Primary Key https://hashitosystem.com/blog/uuid-v7-time-ordered-keys/ ハシトシステム技術ブログ ja 2026-07-31 UUID v7 と時刻順キー — 主キーに使う利点と落とし穴