判断DB中的各个表格数据量

SELECT
relname AS 表名,
pg_size_pretty(pg_total_relation_size(relid)) AS 总大小,
pg_size_pretty(pg_relation_size(relid)) AS 表数据大小,
pg_size_pretty(pg_total_relation_size(relid) - pg_relation_size(relid)) AS 索引大小
FROM
pg_catalog.pg_statio_user_tables
WHERE
schemaname = 'public'
ORDER BY
pg_total_relation_size(relid) DESC
LIMIT 20;