数据库里的可用空间

当我们在一个命名空间中运行数据清除时，数据库的大小和空间并没有改变。  我想，像Oracle一样，它留下的空白空间是可以被缓存使用的，但有没有办法看到这些空间有多少是可用的？  今天我增加了系统可用的磁盘大小，因为我们已经达到了关键的低磁盘空间，然而，随着清理的进行，我们应该有几百GB的可用空间在数据库内使用。  那么，只要数据库中有足够的可用空间用于写入数据，允许系统耗尽可用的磁盘空间是否安全？When we run data purges in a namespace, the size and space of the DB does not change.  I assume like Oracle it leaves white space that is usable by cache, but is there a way to see how much of this space is available?  Today I increased the size of the disk available to the system as we were reaching critical low disk space,  however, with the purges, we should have several hundred GB of available space inside the database to use.  And is it safe to allow the system to run out of available disk space, as long as there is enough free space in the DB for writing data?