February 2026 monthly summary: Implemented a unified storage optimization capability via ALTER TABLE COMPACT in two core repositories, ydb-platform/ydb and ytsaurus/ytsaurus. The feature introduces an ALTER TABLE COMPACT statement to shrink storage and optimize shard usage, with parameters CASCADE and MAX_SHARDS_IN_FLIGHT. Commits: 64569f3ec3dbfee16e6b852fbb44c5a9bcc51b3e (ydb) and f3052f64dfe7e7640d3c1e3ea5616048d1bb7437 (ytsaurus); RFC and GitHub Issue references provided. No formal bug fixes recorded; focus was on feature delivery, consistency, and documentation. Impact: enables customers to reduce storage footprint and better manage shard concurrency; improves maintenance efficiency and platform competitiveness. Skills: SQL DDL design, distributed storage concepts, cross-repo collaboration, documentation, and traceability.

August 2025 accomplishments across ytsaurus/ytsaurus and ydb-platform/ydb: Delivered a new CACHE_MODE option for YQL FAMILY settings, enabling explicit cache behavior control during table creation and alteration. Implemented in backend and parser layers, added serialization for add/alter operations, and introduced comprehensive unit tests. Strengthened input validation to prevent invalid CACHE_MODE usage, including ensuring it's a string literal and not redefined within a single ALTER statement. These changes enable more predictable caching strategies, reduce misconfigurations, and improve reliability of production workloads with minimal risk.