# postgis/

spatial types, spatial predicates, and the indexes that make them fast. almost every postgis performance problem is a query that cannot reach the index.

- [gist-index](/knowledge/databases/postgresql/postgis/gist-index/)
- [st-contains](/knowledge/databases/postgresql/postgis/st-contains/)
- [st-dwithin](/knowledge/databases/postgresql/postgis/st-dwithin/)