Time postgres queries using dtrace - WIP

pg-query.d

#!/usr/bin/env dtrace -s

#pragma D option quiet
#pragma D option switchrate=10hz

/*
   docs:
   http://www.postgresql.org/docs/9.2/interactive/dynamic-trace.html
*/

postgres*::query-start
{
  start = timestamp;
}

postgres*::query-done
{
  end = timestamp;
  elapsed = end - start;

  /* microseconds */
  printf("%d - %s\n\n", (elapsed / 1000), copyinstr(arg0));
}