"no primary key for reasons of efficiency" - That is quite a contradiction.
NHibernate doesn't support entities without id. When you don't specify a name for the <id> tag, it assumes "id". A table without primary key is basically an unordered heap, searches on this must perform a table scan. Highly costly. Put an identity field there, it wouldn't matter to insert performance, and it will keep the table ordered by entry date. > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of > Jeff Brown > Sent: Friday, September 08, 2006 4:28 AM > To: [email protected] > Subject: [Castle-users] ActiveRecord table with no primary key > > I have a table with no primary key for reasons of efficiency. It > basically consists of a bag of timestamped values associated with a > given id. NHibernate seems to support this scenario by specifying an > <id> element with no name, and AR has a suggestive looking > PrimaryKeyType.None but using it throws an exception: > > NHibernate.MappingException > Message: The element 'id' in namespace > 'urn:nhibernate-mapping-2.0' has incomplete content. List of possible > elements expected: 'urn:nhibernate-mapping-2.0:meta urn:nhibernate- > mapping-2.0:column urn:nhibernate-mapping-2.0:generator'. > > I don't really want to add a primary key to this table because I expect > it to get _very_ large. (It contains a stream of performance data > sampled at regular intervals from dozens of sources. I will probably > switch things over to a better persistence mechanism but not now.) > > Jeff. > > ----------------------------------------------------------------------- > -- > Using Tomcat but need to do more? Need to support web services, > security? > Get stuff done quickly with pre-integrated technology to make your job > easier Download IBM WebSphere Application Server v.1.0.1 based on > Apache Geronimo > http://sel.as- > us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 > _______________________________________________ > CastleProject-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/castleproject-users ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ CastleProject-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/castleproject-users
