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On 08/13/2012 07:38 PM, Michael Still wrote:
> 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 at 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?

No, I read the exact same thing in the SQLAlchemy docs and was surprised
to see the column type was MEDIUMTEXT. But I assure you it is :) Just
run devstack and verify!

-jay