On a replicated table, can I add an index without telling Slony?  Say if I have a replicated table foo(a,b,c,...), could I do "create index ifoo on foo(a)" on the master node without using Slony's EXECUTE SCRIPT?

The reason for this is to experiment with performance.  I'm not sure which index might be best, and I don't want to propagate the index to the slave node until I've tested several solutions.

Thanks,
Craig