postgresql - 真空满后释放内存？

Question

我的数据库服务器上的磁盘空间不足。我从未执行过 vacuum full，我希望 vacuum full 可以释放一些空间。

您之前是否运行过vacuum full，如果释放了空间，它有多少？

Answer 1

physically vacuum full 制作一个表的副本并销毁旧表。这导致了几个结论:

• 如果空间不足，您可能无法运行它
• 您将释放与删除的元组占用的空间一样多的空间

https://www.postgresql.org/docs/current/static/sql-vacuum.html

This method also requires extra disk space, since it writes a new copy of the table and doesn't release the old copy until the operation is complete. Usually this should only be used when a significant amount of space needs to be reclaimed from within the table.

您可以通过获取数据的恢复副本来无间隙地找出数据的大小，例如 pg_dump/pg_restore