PostgreSQL comes built-in with a variety of indexes, some of which are further extensible to build powerful new indexing schemes. But what are all these index types? What are some of the special features of these indexes? What are the size & performance tradeoffs? How do I know which ones are appropriate for my application? Fortunately, this talk aims to answer all of these questions as we explore the whole family of PostgreSQL indexes: B-tree, expression, GiST (of all flavors), GIN and how they are used in theory and practice.