What methods can improve the efficiency of information retrieval in PostgreSQL?

To improve the efficiency of information retrieval in PostgreSQL, the following methods can be used:

• Indexes: creating indexes (B-tree, GiST, GIN) on fields involved in searches.
• Full-text search: utilizing built-in full-text search capabilities (tsvector, tsquery) with GIN or GiST indexes.
• Query optimization: analyzing and rewriting queries using EXPLAIN to identify bottlenecks.
• Materialized views: for frequently used complex queries.
• Partitioning tables: if data is very large, to speed up searches in specific sections.
• Caching: using external caches or PostgreSQL's internal mechanisms.

Example of creating a full-text index:

CREATE INDEX idx_fts ON documents USING GIN(to_tsvector('russian', content));

And a query with full-text search:

SELECT * FROM documents WHERE to_tsvector('russian', content) @@ to_tsquery('машинное & обучение');