What index types are used in PostgreSQL besides B-tree?

In PostgreSQL, besides the standard B-tree index, which is used by default, there are several other types of indexes that are applied depending on the task:

• Hash — effective for equality operations but less versatile than B-tree.
• GIN (Generalized Inverted Index) — used for indexing arrays, JSONB, full-text search, and other complex structures.
• GiST (Generalized Search Tree) — suitable for geometric data, full-text search, and other cases where support for custom operators is needed.
• SP-GiST (Space-partitioned GiST) — for specific data structures, such as points in space, prefix trees.
• BRIN (Block Range Index) — effective for very large tables with natural data order, such as time series.

Example of creating a GIN index for a JSONB field:

CREATE INDEX idx_data_gin ON my_table USING GIN (data jsonb_path_ops);

The choice of index type depends on the nature of the data and queries.