/* Index and table hit rate */
SELECT
'index hit rate' AS name, (sum(idx_blks_hit)) / nullif(sum(idx_blks_hit + idx_blks_read),0) AS ratio
FROM pg_statio_user_indexes UNION ALL SELECT
'table hit rate' AS name, sum(heap_blks_hit) / nullif(sum(heap_blks_hit) + sum(heap_blks_read),0) AS ratio
FROM pg_statio_user_tables;