This patch is pretty trivial.
Add modulo operator to pgbench.This is useful to compute a permutation for tests with non uniform accesses (exponential or gaussian), so as to avoid trivial correlations between neighbour keys.
-- Fabien.
diff --git a/contrib/pgbench/pgbench.c b/contrib/pgbench/pgbench.c
index ad55c3c..16744ac 100644
--- a/contrib/pgbench/pgbench.c
+++ b/contrib/pgbench/pgbench.c
@@ -1570,6 +1570,16 @@ top:
}
snprintf(res, sizeof(res), INT64_FORMAT, ope1 / ope2);
}
+ else if (strcmp(argv[3], "%") == 0)
+ {
+ if (ope2 == 0)
+ {
+ fprintf(stderr, "%s: division by zero in modulo\n", argv[0]);
+ st->ecnt++;
+ return true;
+ }
+ snprintf(res, sizeof(res), INT64_FORMAT, ope1 % ope2);
+ }
else
{
fprintf(stderr, "%s: unsupported operator %s\n", argv[0], argv[3]);
diff --git a/doc/src/sgml/pgbench.sgml b/doc/src/sgml/pgbench.sgml
index b7d88f3..9a6ee3b 100644
--- a/doc/src/sgml/pgbench.sgml
+++ b/doc/src/sgml/pgbench.sgml
@@ -735,7 +735,7 @@ pgbench <optional> <replaceable>options</> </optional> <replaceable>dbname</>
Each <replaceable>operand</> is either an integer constant or a
<literal>:</><replaceable>variablename</> reference to a variable
having an integer value. The <replaceable>operator</> can be
- <literal>+</>, <literal>-</>, <literal>*</>, or <literal>/</>.
+ <literal>+</>, <literal>-</>, <literal>*</>, <literal>%</> or <literal>/</>.
</para>
<para>
psql test < pgbench-modulo-test-init.sql ./pgbench -M prepared -f pgbench-modulo-test-run.sql -P 1 -t 100000 -n test psql test < pgbench-modulo-test-check.sql
pgbench-modulo-test-init.sql
Description: application/sql
pgbench-modulo-test-run.sql
Description: application/sql
pgbench-modulo-test-check.sql
Description: application/sql
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