什么是cassandra的墓地压实？

Question

卡桑德拉诺布在这里。在浏览文档等时，我重复地找到了对墓地压实的参考（有时候是墓碑），例如：

$ cassandra-cli 
[default@unknown] help truncate;
...
A snapshot of the data is created, which is deleted asyncronously during a
'graveyard' compaction.

我已经尝试过Google搜索，但这只会涉及更多涉及墓地压缩的地方，例如this，this和this。

墓地压实究竟是什么？当人们提到墓碑时，人们的意思是什么？

Answer 1

Graveyard压缩是一种压缩，可以删除不再需要的SSTable。

例如，在放置期间，在创建快照之后，通过墓地压缩删除相应表的sstables。

A snapshot of the data is created, which is deleted asyncronously during a
'graveyard' compaction.

您在此处找到的只是文档中的错误。它应该说：

A snapshot of the data is created, 
then the data is deleted asyncronously during a 'graveyard' compaction.