yes, for some scenario's this make sense. But do remember that what the db optimize's in this case is that you actually queried these objects (either via a query or lazy loading them) even without you actually using the data.
A "dynamic mapping generation using heuristics" could detect if these objects were actually used and wether it would actually be necessary to do the query or not. So yes, the heuristics should not find out what the optimal joins are at the db-level, but what access pattern that should be used at the object/query level. /max > Hi Max and ppl in the hibernate dev list, > > Talking about the dynamic generation of mappings, one of my Colleague has > found out that there is no real performance improvement by doing this > since > the underlying database will anyway to the necessary optimisations at the > physical layer: Say for example there is this query which does multiple > joins between tables and say that this query is used heavilly by the > application,,, then the database will identify this and aggregate the > necessary tables so that the query will not be involved in any join > operations. > > appreciate you guys feedback/comments on this > > thanks > mahen > > > On 10/19/06, Max Rydahl Andersen <[EMAIL PROTECTED]> wrote: >> >> Hi Mahen, >> >> some have previously talked about utilizing the statistics and aop to >> figure >> out more optimal ways of querying/mapping so it is not a new idea; just >> that >> noone have yet had the time to investigate into it. >> >> I would assume classic database query optimizing techniques and program >> flow analysis >> is applicable in this area so if you know those then simply learn >> hibernate and >> apply them ;) >> >> /max >> >> > Hi All, >> > >> > I am a postgraduate student from Imperial College, London,, >> > >> > I am doing a research on performace optimisations in the peristence >> > layer of >> > a web >> > application... >> > >> > just want to get your ideas on likely improvements that can be done in >> > hibernate to >> > optimise the performance,, >> > these changes should be changes to the hibernate core... >> > >> > yeah,, i have seen various articles on how to increase performace in >> > hibernate and all,, but >> > what i want to know is that what are the areas that i can explore in >> > order >> > to increase >> > the performance more..at the code level >> > >> > i am hoping to try out various optmisations and evaluate the likely >> > impact >> > of each >> > optimisation and stuff like that and would like to contribute to >> > hibernate >> > with my >> > findings,,, >> > >> > greatly appreciate some pointers from you all,, >> > >> > mainly i am concerned about the following disadvantage of hibernate: >> > >> > >> > "Developers must know enough information about data usage at compile >> > time to >> > be able to optimise queries and choose the appropriate >> object-relational >> > mappings" >> > so therefore, i am thinking about the repercussions and advantages of >> > having dynamically generated mapping files based on heuristics of the >> > usage >> > pattern of the data,, in other words dynamically deciding on the >> mapping >> > based on what queries are used more frquently in a system,, >> > >> > would appreciate some feedback from you all >> > >> > Thanks >> > Mahen >> >> >> >> -- >> -- >> Max Rydahl Andersen >> callto://max.rydahl.andersen >> >> Hibernate >> [EMAIL PROTECTED] >> http://hibernate.org >> >> JBoss a division of Red Hat >> [EMAIL PROTECTED] >> -- -- Max Rydahl Andersen callto://max.rydahl.andersen Hibernate [EMAIL PROTECTED] http://hibernate.org JBoss a division of Red Hat [EMAIL PROTECTED] ------------------------------------------------------------------------- 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 _______________________________________________ hibernate-devel mailing list hibernate-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/hibernate-devel
