optimizing-clickhouse-and-hogql-queries

optimizing-clickhouse-and-hogql-queries is a Databases & SQL skill for AI agents, published by PostHog in the posthog repository on GitHub. Skillspace rates optimizing-clickhouse-and-hogql-queries F (45/100) and the safety scan rated it risky; the rating is based on static analysis only.

Workflow for optimizing ClickHouse and HogQL queries. Use when a HogQL query, query runner, insight, or report is too slow; when a hand-written ClickHouse query (via `sync_execute` or in a migration) is too slow; when ClickHouse times out or hits memory limits; when investigating a slow `system.query_log` row; or when reviewing a proposed HogQL printer change for performance. Covers extracting the ClickHouse SQL, common smells (`FROM ... FINAL`, `JSONExtract` over properties, missing skip indexes, self-joins, CTE blow-up), measuring against a real cluster, and applying the fix at the right layer (printer, query runner, or migration). Does NOT cover Postgres / Django ORM / app-database queries; those need pganalyze and the Postgres section of `query-performance-optimization.md`.

Grade
F
Quality
45 / 100
Safety
Risky
GitHub stars
35,560

Unproven: rated by static analysis only, not yet compared head-to-head.

This rating describes the version of the repository we crawled; it may have changed since.

View source on GitHubPostHog/posthog

Our review

Architecture
94 / 100
Maturity
Structured: ships references or scripts
Security scan
High-risk patterns
License
Not declared. Check the repository before reusing it.
Adoption
Adopted by 1 other repositories, in 1 collections

What the scanner flagged

  • references sensitive credential env

Not checked yet

  • Category is a classifier prediction; no model has read this skill yet
  • Not judged on the rubric yet (not a contender in its category)
  • No blind task eval yet
  • Scope (portable / vendor / repo-internal) not assessed; only the top of each category is read for scope
  • Sibling files (scripts, references) not fetched; security scan covers SKILL.md only

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