Exceeded memory during rs_count

[jeffrc2]

I0529 19:57:49.547868   118 rs_count.cc:259] Using 4 threads...
I0529 19:57:49.548871   118 rs_count.cc:180] Loading selected keys ..
I0529 19:58:18.948146   118 rs_count.cc:202] Building the index ...
I0529 19:58:18.949110   118 rs_count.cc:203] There are totally 17499560 keys
terminate called after throwing an instance of 'std::bad_alloc'
  what():  std::bad_alloc
Aborted (core dumped)

real    0m29.423s
user    0m24.547s
sys     0m4.859s

The testing system has 16GB RAM. It appears that the memory used is being exceeded.