gorm-sql-query-performance

name	gorm-sql-query-performance
description	GORM + PostgreSQL query performance review. Use when optimizing slow queries, designing indexes, analyzing N+1 patterns, or configuring connection pools. Trigger on "slow", "optimize", "index", "EXPLAIN", "N+1", or performance degradation.
license	MIT
metadata	{"author":"saifoelloh","version":"1.0.0","parent_skill":"gorm-sql-best-practices","sources":["Use The Index, Luke (use-the-index-luke.com)","PostgreSQL 16 Official Documentation","GORM Official Documentation (gorm.io/docs)"],"last_updated":"2026-03-13"}

Query Performance

Expert-level performance review for GORM + PostgreSQL queries. Detects N+1 patterns, missing indexes, connection pool misconfigurations, and memory-inefficient data fetching.

When to Apply

Use this skill when:

• An endpoint is slow or degrading under load
• Reviewing repository code for N+1 query patterns
• Designing indexes for new tables or query patterns
• Investigating connection pool exhaustion
• Processing large datasets in background jobs

Rule Categories

Priority	Count	Focus
Critical	2	N+1 queries, unindexed foreign keys
High	3	EXPLAIN ANALYZE, connection pool, batch processing
Medium	2	COUNT vs len(), partial indexes

Rules Covered (7 total)

Critical Issues (2)

• critical-n-plus-one — Detect and eliminate N+1 query patterns using Preload
• critical-unindexed-fk — Index foreign keys and all WHERE clause columns

High-Impact Patterns (3)

• high-explain-analyze — Use EXPLAIN (ANALYZE, BUFFERS) before declaring a query optimized
• high-connection-pool — Configure connection pool parameters explicitly for production
• high-find-in-batches — Use FindInBatches for large dataset processing

Medium Improvements (2)

• medium-count-query — Use db.Count instead of len() on full fetch
• medium-partial-index — Use partial indexes for filtered queries on large tables

Trigger Phrases

• "Why is this query slow?"
• "Optimize this query"
• "Check for N+1"
• "Add an index"
• "EXPLAIN output"
• "Performance issue"
• "Connection pool"
• "Process large dataset"

Related Skills

• gorm-query-patterns — For ORM patterns that cause N+1
• postgresql-syntax — For ILIKE and index-aware SQL syntax
• migration-safety — For CREATE INDEX CONCURRENTLY in migrations