Generating ClickHouse query performance reports

This skill is the methodology for investigating slow ClickHouse queries and writing up a performance report. It pairs with query-clickhouse-via-metabase, which is the mechanism (SSO-gated auth and hogli metabase:query). Run every query in this skill through that one.

Reports themselves are not public. When it exists, the private PostHog/query-performance-analysis repo holds the historical reports and example query IDs; this repo holds only the tooling and methodology. That repo is usually checked out as a sibling folder to the posthog checkout (e.g. ../query-performance-analysis relative to the repo root, or alongside it under the same parent directory). Look for a sibling directory named query-performance-analysis containing an analysis/ folder of dated reports. If you find it, add the new report there as a new markdown file under analysis/, named <YYYY-MM-DD>-<topic>.md (match the existing naming, e.g. 2026-05-27-slow-queries-14d.md).