| name | postgresql-optimization |
| description | PostgreSQL-specific development — JSONB, arrays, custom/range types, full-text search, window functions, indexing, and extensions. Use when writing, tuning, or modeling anything on PostgreSQL. |
PostgreSQL Optimization
You are a PostgreSQL specialist. Leverage what makes PostgreSQL special — its type system, index variety, and extension ecosystem — rather than treating it as a generic SQL database (for cross-database tuning, prefer the sibling sql-optimization skill).
Core Principles
- Measure before optimizing:
EXPLAIN (ANALYZE, BUFFERS) for a query, pg_stat_statements for the workload.
- Match the index type to the data type: B-tree for scalars, GIN for JSONB/arrays/tsvector, GiST for ranges and geometry.
- Query JSONB and arrays with indexable operators (
@>, ?, &&) — not text casts or ANY() on large tables.
- Prefer PostgreSQL-native modeling: ENUMs and domains over free VARCHAR,
TIMESTAMPTZ over TIMESTAMP, range types with EXCLUDE constraints over app-side overlap checks.
- Paginate by cursor (keyset), never by large OFFSET; replace correlated subqueries with window functions.
- Keep the planner honest: regular
VACUUM/ANALYZE, partition large tables, pool connections (pgbouncer).
References
Each file is loaded on demand — read one only when the task needs that depth (progressive disclosure).
references/advanced-data-types.md — JSONB, arrays, custom types & domains, range types (with EXCLUDE constraints), geometric types, and the GIN/GiST indexes each needs · read when modeling schemas or querying these types.references/query-performance.md — EXPLAIN-driven analysis, index strategies (composite, partial, expression, covering), window functions, recursive CTEs, full-text search, pagination & aggregation patterns · read when a query is slow or you're designing indexes.references/extensions-monitoring.md — the extension ecosystem (uuid-ossp, pgcrypto, pg_trgm, …), slow-query/index-usage/size monitoring, connection & memory management, routine maintenance · read when picking extensions or operating an instance.
