Hello Mutsumara-san,
#3. Documentation
I think modulo operator explanation should put at last at the doc line.
Because the others are more frequently used.
So I like patch3 which is simple and practical.
Ok.
If you agree or reply my comment, I will mark ready for commiter.
Please find attached v4, which is v3 plus an improved documentation
which is clearer about the sign of the remainder.
--
Fabien.
diff --git a/contrib/pgbench/pgbench.c b/contrib/pgbench/pgbench.c
index 2f7d80e..a815ad3 100644
--- a/contrib/pgbench/pgbench.c
+++ b/contrib/pgbench/pgbench.c
@@ -1574,6 +1574,22 @@ top:
}
snprintf(res, sizeof(res), INT64_FORMAT, ope1 / ope2);
}
+ else if (strcmp(argv[3], "%") == 0)
+ {
+ int64_t remainder;
+ if (ope2 == 0)
+ {
+ fprintf(stderr, "%s: division by zero in modulo\n", argv[0]);
+ st->ecnt++;
+ return true;
+ }
+ /* divisor signed remainder */
+ remainder = ope1 % ope2;
+ if ((ope2 < 0 && remainder > 0) ||
+ (ope2 > 0 && remainder < 0))
+ remainder += ope2;
+ snprintf(res, sizeof(res), INT64_FORMAT, remainder);
+ }
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 b479105..66ec622 100644
--- a/doc/src/sgml/pgbench.sgml
+++ b/doc/src/sgml/pgbench.sgml
@@ -735,7 +735,9 @@ 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>/</>.
+ The modulo operation (<literal>%</>) is based on the floored division, so
+ that the remainder keeps the sign of the divisor.
</para>
<para>
--
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