postgres-query-performance-reviewlisted

# Outcome Produce a concrete, reviewable result for the workflow below without overstating what was observed, executed, or verified. ## Compatibility Portable across Claude Code, Codex, and OpenCode. Plan interpretation targets PostgreSQL 18; check it against the deployed version and provider. The optional Python 3.11 helper parses local EXPLAIN JSON only and never connects to PostgreSQL or executes SQL. ## Use this skill when - A statement or normalized query family misses a latency, throughput, or resource budget. - An EXPLAIN or EXPLAIN ANALYZE plan needs safe, evidence-based interpretation. - Parameter skew, generic/custom plans, stale statistics, join choice, spills, or repeated work may explain instability. - A performance recommendation needs a correctness-preserving experiment and success metric. ## Do not use this skill when - The task is greenfield modeling, constraints, tenancy, or RLS design; use `postgres-schema-design`. - The task is a broad deployed-schema audit; use `postgres-schema-review`. - The bottleneck is established and the deliverable is an exact index proposal; use `postgres-index-design`. - The deliverable is rollout mechanics for an approved query/schema change; use `postgres-migration-safety`. ## Inputs Inspect or obtain: - PostgreSQL version/provider, instance/storage context, relevant planner and memory settings, and observation window. - Sanitized SQL shape, statement identifier, parameter classes, transaction/isolation context, and pr