GUIDs themselves have a fairly low chance of reptition although it does happen. Unfortunately the Guid.Comb algorithm breaks down quickly when is distributed situations such as the one you are describing (read the comments from here: http://www.lostechies.com/blogs/derickbailey/archive/2009/07/14/database-id-int-vs-bigint-vs-guid.aspx )
If you really, really need sequential Ids (which TBH likely you don't) then you are best off by letting the DB do it. My option in this case would be to use HiLo however. That lets the DB be the point of truth (which is what you want) but saves the overhead of Identity (etc) type identifiers. You Ids wont be completely sequential however. There is some good tech out on the net about NH identifiers and the drawbacks of each. On Wed, Feb 17, 2010 at 10:55 PM, Chris J <[email protected]> wrote: > > I am evaluating using NHibernate as the ORM for our platform. In our > environment, there are multiple servers performing operations on the > database. I'd like to be able to use sequential IDs when adding new > records to certain tables. I have read about and experimented with the > 'guid.comb' ID generator. > > If I were to use guid.comb for ID generation on multiple servers, how > would that affect table fragmentation on database (SQL Server)? Is > there any risk of ID collision when more than one server is adding > records with guid.comb as the ID generator? > > Thanks. > > -- > You received this message because you are subscribed to the Google Groups > "nhusers" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]<nhusers%[email protected]> > . > For more options, visit this group at > http://groups.google.com/group/nhusers?hl=en. > > -- You received this message because you are subscribed to the Google Groups "nhusers" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/nhusers?hl=en.
