I know this.... but what I am saying is that if my objects have a large number of properties and a few joins between objects then the resulting SQL that NHibernate produces contains a large number of columns (most of which I don't need). I just want to know if this has any performance implications for my application.
On Oct 29, 4:12 am, Fabio Maulo <[email protected]> wrote: > with NH, in general, you are querying objects not columns. > If you like query something else than > objectshttp://nhforge.org/doc/nh/en/index.html#d0e10116 > > 2009/10/28 reach4thelasers <[email protected]> > > > > > > > One of my main objects in my domain model has about 50 properties > > including about 20 many-to-one foreign key relationships. I thought I > > would gain performance by splitting the table into 2 seperate tables > > using a lazy one-to-one relationship; keeping the most-used properties > > on one side and the less frequently used properties on the other. > > This was a waste of time since one-to-one relationships cannot be lazy > > and results in a second query meaning performance is even lower! > > > In SQL we usually select only the columns we need ...select > > col1,col2,col3 from..... but in NHibernate this cannot be done and > > NHibernate returns all the columns that are mapped for that object. > > The number of columns become huge when you start joining up objects > > together, each joined object returning all the mapped columns for that > > object. > > > I am concerned that if I run an HQL query with a few joins that > > returns 100 columns (only 10 of which I need) that the performance of > > my application will be affected. Is this the case? Can anyone advise > > by how much performance is affected? or is it minimal? > > -- > Fabio Maulo --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
