PostGIS Cookbook - Second Edition

How it works...

Database indices help us quickly and efficiently find the values we are interested in. Generally, a query using an index is faster than one that is not, but the performance improvement may not be to the degree found in this recipe.

Additional information about PostgreSQL and PostGIS indices can be found at the following links:

• https://www.postgresql.org/docs/9.6/static/indexes.html
• https://postgis.net/docs/using_postgis_dbmanagement.html#idm2267

We will discuss query plans in greater detail in a later recipe in this chapter. By understanding query plans, it becomes possible to optimize the performance of deficient queries.