Benchmark: timing 10000 iterations of query_dbh, query_mem...
 query_dbh:  6 wallclock secs ( 3.87 usr +  0.92 sys =  4.79 CPU) @ 2087.68/s (n=10000)
 query_mem:  6 wallclock secs ( 2.51 usr +  1.23 sys =  3.74 CPU) @ 2673.80/s (n=10000)