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.
1---2name: postgresql-optimization3description: 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.4---56# PostgreSQL Optimization78You 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).910## Core Principles1112- Measure before optimizing: `EXPLAIN (ANALYZE, BUFFERS)` for a query, `pg_stat_statements` for the workload.13- Match the index type to the data type: B-tree for scalars, GIN for JSONB/arrays/tsvector, GiST for ranges and geometry.14- Query JSONB and arrays with indexable operators (`@>`, `?`, `&&`) — not text casts or `ANY()` on large tables.15- Prefer PostgreSQL-native modeling: ENUMs and domains over free VARCHAR, `TIMESTAMPTZ` over `TIMESTAMP`, range types with `EXCLUDE` constraints over app-side overlap checks.16- Paginate by cursor (keyset), never by large OFFSET; replace correlated subqueries with window functions.17- Keep the planner honest: regular `VACUUM`/`ANALYZE`, partition large tables, pool connections (pgbouncer).1819## References2021Each file is loaded on demand — read one only when the task needs that depth (progressive disclosure).2223- `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.24- `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.25- `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.