Use “distinct” to filter redundant types from pg_typeto reduce memory bloat...

Use “distinct” to filter redundant types from pg_typeto reduce memory bloat especially in multi-schema structure database

activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb

@@ -568,13 +568,13 @@ def load_additional_types(type_map, oids = nil)
 
           if supports_ranges?
             query = <<-SQL
-              SELECT t.oid, t.typname, t.typelem, t.typdelim, t.typinput, r.rngsubtype, t.typtype, t.typbasetype
+              SELECT DISTINCT on (t.typname) t.oid, t.typname, t.typelem, t.typdelim, t.typinput, r.rngsubtype, t.typtype, t.typbasetype
               FROM pg_type as t
               LEFT JOIN pg_range as r ON oid = rngtypid
             SQL
           else
             query = <<-SQL
-              SELECT t.oid, t.typname, t.typelem, t.typdelim, t.typinput, t.typtype, t.typbasetype
+              SELECT DISTINCT on (t.typname) t.oid, t.typname, t.typelem, t.typdelim, t.typinput, t.typtype, t.typbasetype
               FROM pg_type as t
             SQL
           end