When we create a pk in PostgreSQL, an index named table_name_pkey is automatically created.
The following script gives all indexes, those created by the pk’s and the others.
Don’t forget that PostgreSQL does not create automatically an index when you create a fk. You have to do it yourself !
By the way, this script works for composite indexes thanks to the handy function array_to_string that creates of comma separated list of the column names. It works because the two first columns in the select clause are given in the order by.
select t.relname as table_name ,i.relname as index_name ,array_to_string(array_agg(a.attname), ', ') as column_names from pg_class t ,pg_class i ,pg_index ix ,pg_attribute a where t.oid = ix.indrelid and i.oid = ix.indexrelid and a.attrelid = t.oid and a.attnum = any(ix.indkey) and t.relkind = 'r' -- takes regular tables and t.relname not like 'pg_%' -- excludes system catalogs group by t.relname ,i.relname order by t.relname ,i.relname;
By the way, when I was working on the script, I was listening one of the last masterworks of the Johann Sebastian Bach of our time : Pulse of Steve Reich. The music of Steve Reich is a good music to listen when you write programs because this music is well structured and transmits lofty feelings…