postgres-patterns

To optimize PostgreSQL queries, use B-tree indexes for standard equality and range lookups, GIN indexes for JSONB or array columns, and BRIN indexes for large, physically sorted tables. Selecting the correct index type resolves slow query performance by ensuring efficient data retrieval.

Cursor pagination in a PostgreSQL schema is best implemented using ordered, indexed columns to track the last fetched row. This approach avoids the performance overhead of OFFSET clauses on large datasets and provides stable, efficient pagination results.

Row Level Security (RLS) in PostgreSQL works by attaching security policies directly to tables, restricting query access to specific rows based on the current user. Implementing RLS policies ensures database-level access control and enforces data isolation.

Filtering PostgreSQL JSONB columns slows down when missing appropriate indexing. Creating GIN indexes on the JSONB column accelerates containment and key lookup operations, resolving the anti-pattern of sequentially scanning large JSON payloads.

Use a covering index in PostgreSQL when you want to satisfy a query entirely from the index without accessing the table, including columns in the INCLUDE clause. A composite index is preferred when multiple columns are actively filtered or joined together in WHERE clauses.