[sqlite] journal files and database corruption

[Will Leshner]

In the article about locking and concurrency on the SQLite website,  
where it talks about how to corrupt a SQLite database, it says that a  
SQLite database can be corrupted if a hot journal file is missing  
when SQLite reconnects to the database. What kind of corruption are  
we talking about, exactly? Is it that the data in the database is  
inconsistent, in the sense that only some of the data has been  
written with no way to roll any of it back? Or is this a more serious  
kind of corruption in which the database file becomes completely  
unusable? I guess I'd always thought the latter, but after reading  
through the article more carefully, I am now thinking it might be the  
former. If it is the former, it might be useful to make that explicit  
in the article. While having an inconsistent database is certainly a  
BadThing, having a completely unusable database (one that SQLite  
can't even open anymore) is far worse, in my opinion.

Thanks.