Find missing indexes on tables

indexusage.sql

SELECT
	relname,
	seq_scan - idx_scan AS too_much_seq,
	CASE
WHEN seq_scan - idx_scan > 0 THEN
	'Missing Index?'
ELSE
	'OK'
END,
 pg_relation_size (relname :: regclass) AS rel_size,
 seq_scan,
 idx_scan
FROM
	pg_stat_all_tables
WHERE
	schemaname = 'public'
AND pg_relation_size (relname :: regclass) > 80000
ORDER BY
	too_much_seq DESC;
	
	
	
	
This checks if there are more sequence scans then index scans. 
If the table is small(<80000), it gets ignored, 
since postgres seems to prefere sequence scans for them.