Re: Can Innodb reuse the deleted rows disk space?

[Chris]

leo huang wrote:
> hi, Chris
> 
> 
>> I'm sure it will, what makes you think it won't?
> Because some paper say that when the row is deleted or update, Innodb
> just make a mark that the row is deleted and it didn't delete the
> rows. I can't find more information about the re-use tablespace. Can
> you give me more?

That's the way MVCC works. If you need full acid/transaction support, 
that's the only way it can do it (postgresql works exactly the same 
way). It can't just delete the row because you might roll back the 
transaction and it will have to undo that delete, or other transactions 
might be using it for whatever purpose.

http://dev.mysql.com/doc/refman/5.1/en/innodb-multi-versioning.html
http://dev.mysql.com/doc/refman/5.1/en/file-space-management.html