Fedora utilizes primary key indexes on its tables. These indexes do not work efficiently for some types of queries ( LIKE ) if your Postgres database's LC_COLLATE setting is anything other than C (for example en_US.utf8 ).
Fedora accounts for this by creating a secondary index ( resources_idx2 ) to allow it to continue working efficiently.
You can avoid the creation of a second index by configuring your Postgres server with a locale of C. More details on Postgres's LOCALE support can be found in Section 23.1 of the Postgres manual.