ClickHouse

Scaffold or review a feature design document for ClickHouse / Antalya. Use this whenever a developer wants to design or implement a new feature, add a SQL function, add a setting, add a new engine or format, or change server behavior in a non-trivial way — even if they don't explicitly ask for a "design doc". Also use when reviewing an existing design before implementation starts.

Use when asked to review a PR, commit, commit range, branch, patch, or pasted diff for duplicated functionality, reinvented wheels, not-invented-here patterns, parallel abstractions, inconsistent naming, inconsistent settings/APIs/schemas/metrics/errors/logs, redundant config keys, non-standard implementations, or places where new code should reuse, generalize, extend, or align with existing codebase patterns and user-facing conventions. Triggers on phrases like "review for duplication", "consistency review", "is this already implemented", "does this match our conventions", "reinventing the wheel".

Use when the user asks for a multi-perspective review of a ClickHouse / C++ diff, PR, branch, commit range, or commit hash. Triggers on requests like "review this PR", "umbrella review", "ubrella review", "do a full review", "deep review of branch X", or any ClickHouse code review where multiple independent angles (security, perf, concurrency, lifetime, compat, tests, etc.) should be considered before producing a consolidated report.

Perform deep feature audits with transition-matrix and logical fault-injection validation. Use when reviewing complex changes, regressions, state-machine behavior, config interactions, API/protocol flows, and concurrency-sensitive logic.

Generate PR descriptions for ClickHouse/ClickHouse that match maintainer expectations. Use when creating or updating PR descriptions.

Review a ClickHouse Pull Request for correctness, safety, performance, and compliance. Use when the user wants to review a PR or diff.