POSTGRE -PG_STATITATINT ADUCUM超时

Question

在我的Aurora Postgres服务器中，我每分钟都会不断看到真空超时：

autovacuum: VACUUM pg_catalog.pg_statistic 

我尝试手动进行操作并进行以下输出：

INFO:  vacuuming "pg_catalog.pg_statistic"
INFO:  "pg_statistic": found 0 removable, 409109 nonremovable row versions in 19981 out of 19990 pages
DETAIL:  408390 dead row versions cannot be removed yet, oldest xmin: 4230263474
There were 0 unused item identifiers.
Skipped 0 pages due to buffer pins, 9 frozen pages.
0 pages are entirely empty.
CPU: user: 0.06 s, system: 0.00 s, elapsed: 0.07 s.
INFO:  vacuuming "pg_toast.pg_toast_2619"
INFO:  "pg_toast_2619": found 0 removable, 272673 nonremovable row versions in 61558 out of 61558 pages
DETAIL:  219 dead row versions cannot be removed yet, oldest xmin: 4230263474
There were 0 unused item identifiers.
Skipped 0 pages due to buffer pins, 0 frozen pages.
0 pages are entirely empty.
CPU: user: 0.14 s, system: 0.00 s, elapsed: 0.14 s.
VACUUM

Query returned successfully in 5 secs 55 msec.

任何人都可以指出发生这种情况的原因吗？

Answer 1

我认为您的Autovacuum可能也可以正常工作，可能只是AWS的指标

一个过程正在以基于成本的真空延迟点等待。

最相似的设置是 autovacuum_vacuum_cost_delay 存在于PostgreSQL中。

想要减慢自动赛。当完成 autovacuum_vacuum_cost_limit 成本时，Autovacuum将为许多毫秒而睡觉。

我们可以尝试使用 PG_STAT_USER_TABLES 来验证Autovacuum的最新时间。

SELECT
  schemaname, relname,
  last_autovacuum,
  last_autoanalyze
FROM pg_stat_user_tables;