Ayende Rahien wrote: > "no primary key for reasons of efficiency" - That is quite a contradiction. > > A table without primary key is basically an unordered heap, searches on this > must perform a table scan. Highly costly.
you would assume that he has indexed access paths, where non unique indexes are put on (id, time stamp). Srdjan >> -----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 > ------------------------------------------------------------------------- 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
