postgres index usage

SELECT 
    schemaname,
    relname AS table_name,
    indexrelname AS index_name,
    idx_scan AS scans,
    pg_size_pretty(pg_relation_size(indexrelid)) AS index_size_pretty,
    pg_relation_size(indexrelid) AS index_size_bytes,
    idx_tup_read,
    idx_tup_fetch
FROM pg_stat_user_indexes
ORDER BY idx_scan DESC
LIMIT 50;