Question

我的postgres数据库（版本8.2.3）显示的大小为24 GB。

为了得到这个数字，我执行这个查询：

SELECT
  oid, datname, pg_database_size(datname) as actualsize, 
  pg_size_pretty(pg_database_size(datname)) as size 
FROM pg_database 
ORDER BY datname

但是，执行此查询时，同一数据库中各个表的大小不会增加24 GB：

SELECT 
  schemaname, tablename, pg_size_pretty(size) AS size_pretty, 
  pg_size_pretty(total_size) AS total_size_pretty 
FROM
  (SELECT *, pg_relation_size(schemaname||'.'||tablename) AS size, 
   pg_total_relation_size(schemaname||'.'||tablename) AS total_size 
   FROM pg_tables where schemaname = 'public') AS TABLES 
ORDER BY total_size DESC;

我已经用漂亮的大小和total_size总结了各个表的大小，但是值不匹配：

我的大小相当于3.5 GB

我的total_size_pretty为5.2 GB。

我在哪里可以找出剩余的总空间用于什么？

Answer 1

通常我使用以下两个查询来获取数据库对象的大小。希望这会有所帮助。

SELECT pg_size_pretty(sum(pg_relation_size(pg_class.oid))::bigint), nspname,
CASE pg_class.relkind WHEN 'r' THEN 'table' WHEN 'i' THEN 'index' WHEN 'S' THEN 'sequence' WHEN 'v' THEN 'view' WHEN 't' THEN 'toast' ELSE pg_class.relkind::text END
FROM pg_class
LEFT OUTER JOIN pg_namespace ON (pg_namespace.oid = pg_class.relnamespace)
GROUP BY pg_class.relkind, nspname
ORDER BY sum(pg_relation_size(pg_class.oid)) DESC;

-

SELECT pg_size_pretty(pg_relation_size(pg_class.oid)), pg_class.relname, pg_namespace.nspname,
CASE pg_class.relkind WHEN 'r' THEN 'table' WHEN 'i' THEN 'index' WHEN 'S' THEN 'sequence' WHEN 'v' THEN 'view' WHEN 't' THEN 'TOAST' ELSE pg_class.relkind::text END
FROM pg_class 
LEFT OUTER JOIN pg_namespace ON (pg_namespace.oid = pg_class.relnamespace)
ORDER BY pg_relation_size(pg_class.oid) DESC;

Answer 2

所有索引和大对象的总大小是多少？

postgresql总数据库大小不匹配各个表大小的总和

2 个答案: