This is a simple guide to working with PostgreSQL, covering key concepts like indexes and the PARTITION BY clause.
Indexes in PostgreSQL are used to speed up data retrieval operations on a database table. They work similarly to an index in a book, allowing the database to quickly locate rows without scanning the entire table.
PostgreSQL supports several types of indexes:
- B-Tree: Default index type, suitable for equality and range queries.
- GIN (Generalized Inverted Index): Useful for full-text search and multi-value data (e.g., arrays, JSON).
- GiST (Generalized Search Tree): Suitable for geometric and text search.
- BRIN (Block Range Index): Efficient for large tables with sorted data.
- Hash: Optimized for equality comparisons.
To create an index, use the CREATE INDEX statement:
-- Basic B-Tree Index
CREATE INDEX idx_user_email ON users (email);
CREATE EXTENSION pg_tgrim;
-- GIN Index for Full-Text Search
CREATE INDEX idx_trgm_user_name ON users USING gin (name gin_trgm_ops);
