/* 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;