Some Scaling Tests
Problem domain: trying to match positions of two sets of stars, photographed at different wavelengths.
Create federated database containing a star database for each wavelength
“loop” over all stars in one database, and find the nearest star in the other
- using the class iterators provided by Obj’y, with a selection using standard C++ e.g.
if(xlow< && x< && ylow< && y<)
- using the iterator with an Obj’y predicate e.g.
sprintf(pred,”x>%f && x<%f && y>%f && y<%f”,xlow,xhigh, …)
Itr.scan(dbH,oocRead,oocAll,pred)
- using an index on (x,y) in the other database, with a lookup key (using ooGreaterThanLookupField etc. etc.)
- NB Obj’y indexes over databases and federations known to be buggy: therefore put the stars in a container, and index over the container