GiST indexes

Generalized Search Tree (GiST) indexes are highly important index types because they are used for a variety of different things. GiST indexes can be used to implement R-tree behavior, and it is even possible for them to act as B-trees. However, abusing GiST for B-tree indexes is not recommended.

Typical use cases for GiSTs are as follows:

• Range types
• Geometric indexes (for example, ones that are used by the highly popular PostGIS extension)
• Fuzzy searching