On May 22, 2008, at 7:10 AM, Geoff wrote:
> > Hi, > > I have split up my database horizontally and am using UUIDs to > uniquely identify a row across databases. Using UUIDs as a primary key > is slow (InnoDB) so I wanted to use the common trick of having a INT > primary key using auto_increment on each database. This is all fine, > until sqlalchemy checks its cache of objects after a query to see if > the object has already been retrieved. This breaks because the primary > key is not unique across databases when I use an auto_incremented INT. > > I reckon the solution is going to have to be manually setting the > field used by sqlalchemy to make the cache decision. Is there any way > of doing this already, or am I going to have to put it in myself? setup the mapper() to have a composite primary key consisting of the autoincremented integer and the UUID column. Use the primary_key option on mapper() to achieve this. (also why is using a UUID "slow" ? if the column is indexed, the difference between int/string would be miniscule compared to the fact that you're using Python and not hardcoded C as the application platform...) --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To post to this group, send email to sqlalchemy@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en -~----------~----~----~----~------~----~------~--~---
