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 to act as b-tree. However, abusing GiST for b-tree indexes is not recommended.

Typical use cases for GiST are as follows:

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