Hash indexes are faster than btree indexes?
This is buried in a few other comments, but it bears repeating as it's perhaps far more important than any performance gains you'd receive from hash indexes over btree... Hash indexes are not crash safe and not WAL logged. This means if you're running with high availability or even using something for disaster recovery like WAL-E[1] and need to recover your database your index would not be in a working state after recovery. Instead you'd need to reindex that data.For any real production database hash indexes should be used with extreme caution if used at all.[1]. https://github.com/wal-e/wal-e