GIN or GiST — which is better for full-text search?

GIN (Generalized Inverted Index) and GiST (Generalized Search Tree) are two types of indexes in PostgreSQL used for full-text search, but they have different characteristics.

• GIN is optimized for fast searches over large volumes of data and is often used for full-text search because it indexes individual lexemes (words). It provides high search speed but takes up more space and updates more slowly.

• GiST is more versatile, supporting various data types and queries, including full-text search, but is generally slower than GIN and requires less space.

For full-text search, it is usually preferable to use GIN because it offers faster query processing and is better suited for text search. GiST can be useful if additional capabilities are needed or if a compromise between speed and index size is desired.

Example of creating a GIN index for full-text search:

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