Find missing indices
To find tables that need indices, run:
SELECT
relname as table_name,
idx_scan as index_scan,
seq_scan as table_scan,
100*idx_scan / (seq_scan + idx_scan) as index_usage,
n_live_tup as rows_in_table
FROM
pg_stat_user_tables
WHERE
seq_scan + idx_scan > 0 -- at least one query
and n_live_tup > 1000 -- at least 1000 rows
and 100*idx_scan / (seq_scan + idx_scan) < 99 -- less than 99% index usage
ORDER BY 4 DESC
LIMIT 10;
This will show tables with low index usage.