openstack team mailing list archive

[Michael Still <michael.still@xxxxxxxxxxxxx>]

On 14/08/12 08:54, Jay Pipes wrote:

> I was *going* to create a random-data table with the same average row
> size as the instances table in Nova to see how long the migration would
> take, and then I realized something... The user_data column is already
> of column type MEDIUMTEXT, not TEXT:
> 
> jpipes@uberbox:~$ mysql -uroot nova -e "DESC instances" | grep user_data
> user_data	mediumtext	YES		NULL	
> 
> So the column can already store data up to 2^24 bytes long, or 16MB of
> data. So this might be a moot issue already? Do we expect user data to
> be more than 16MB?

The bug reports truncation at 64kb. The last schema change I can see for
that column is Essex version 82, which has:

$ grep user_data *.py
082_essex.py:        Column('user_data', Text),

http://docs.sqlalchemy.org/en/latest/dialects/mysql.html says that Text
is "MySQL TEXT type, for text up to 2^16 characters".

Am I misunderstanding something here?

Mikal