diff --git a/contrib/pgbench/pgbench.c b/contrib/pgbench/pgbench.c index ce35bd3dff57a1fae98731550b6787c1c01356bd..b5082e0abd62efb9d1a7e68eb7b1d1e149ce5713 100644 --- a/contrib/pgbench/pgbench.c +++ b/contrib/pgbench/pgbench.c @@ -1,5 +1,5 @@ /* - * $PostgreSQL: pgsql/contrib/pgbench/pgbench.c,v 1.75 2007/12/11 02:31:49 tgl Exp $ + * $PostgreSQL: pgsql/contrib/pgbench/pgbench.c,v 1.76 2008/03/10 01:23:04 tgl Exp $ * * pgbench: a simple benchmark program for PostgreSQL * written by Tatsuo Ishii @@ -191,11 +191,15 @@ usage(void) fprintf(stderr, "(initialize mode): pgbench -i [-h hostname][-p port][-s scaling_factor] [-F fillfactor] [-U login][-d][dbname]\n"); } -/* random number generator */ +/* random number generator: uniform distribution from min to max inclusive */ static int getrand(int min, int max) { - return min + (int) (((max - min) * (double) random()) / MAX_RANDOM_VALUE + 0.5); + /* + * Odd coding is so that min and max have approximately the same chance of + * being selected as do numbers between them. + */ + return min + (int) (((max - min + 1) * (double) random()) / (MAX_RANDOM_VALUE + 1.0)); } /* call PQexec() and exit() on failure */