Solr join query takes too long

[Aashish Agarwal]

Hi

I am using join query that joins 2 cores to get result. Since, number of
docs in both the cores are too high so I want to use post filter with join
query. But that is not working by providing cost=100.

Is it implemented for join filter query? I use solr 4.6.0

Thanks,
Aashish