fprintf(stderr," -x do transactions (one transaction per iteration) (default: no transactions at all)\n");
fprintf(stderr," --keysize KEYSIZE sets the key size (default 8)\n");
fprintf(stderr," --valsize VALSIZE sets the value size (default 8)\n");
fprintf(stderr," --cachesize CACHESIZE set the database cache size\n");
fprintf(stderr," --pagesize PAGESIZE sets the database page size\n");
fprintf(stderr," n_iterations how many iterations (default %lld iterations of %d items per iteration)\n",default_n_items/ITEMS_TO_INSERT_PER_ITERATION,ITEMS_TO_INSERT_PER_ITERATION);