How list all the indexes along with their type (BTREE, BRIN, HASH etc…)

Question

I'm querying to the system catalog in Postgresql 9.6.4

Getting a result set of tables and their indexes is straight forward,what I'm missing is the index type (BTREE, BRIN, etc..) I can't seem to find the type of index anywhere in the system catalogs.

How can I query the catalogs to get a list of indexes along with their type?

Answer 1

The types of indexes in Postgresql are stored in the pg_am catalog table. So to get a list of all tables and their indexes with the index type (or access method ("am") as PostgreSQL calls it) you can run the following

SELECT tab.relname, cls.relname, am.amname
FROM pg_index idx 
JOIN pg_class cls ON cls.oid=idx.indexrelid
JOIN pg_class tab ON tab.oid=idx.indrelid
JOIN pg_am am ON am.oid=cls.relam;