MFC of ZFSv15

[Ivan Voras]

On 09/16/10 12:42, Guido Falsi wrote:

> Related to this, I have a question.
>
> Is it convenient to put databases on a compresed filesystem? Apart from
> the space advantage, does it give any speed advantage/penalty?

It depends on what you do. It will not save you memory usage either 
since data needs to be decompressed when read.

If the database is lightly loaded I don't think there will ever be 
problems. Also if the database is mostly read-only. If it's used in a 
heavy loaded read+write environment or if it is CPU-bound, it is 
probably a bad idea to put it on a compressed file system.

> Anyone has some benchmark or objective data about this?

I know about this one:

http://don.blogs.smugmug.com/2008/10/13/zfs-mysqlinnodb-compression-update/

But it only really measures copy (cp) speeds and compression, not 
database performance.

> Also are we talking about MyISAM or InnoDB tables? Or a mix of those?

MyISAM would probably be faster to compress and manage :)

http://www.scribd.com/doc/14603831/Optimizing-MySQL-Performance-with-ZFS