From 08a4d519e0c73d0f16acd9e5db9e5b547a884902 Mon Sep 17 00:00:00 2001
From: Raul Marin <rmrodriguez@cartodb.com>
Date: Fri, 13 Oct 2017 17:42:23 +0200
Subject: [PATCH] Add pow() support to pgbench

---
 doc/src/sgml/ref/pgbench.sgml                | 7 +++++++
 src/bin/pgbench/exprparse.y                  | 3 +++
 src/bin/pgbench/pgbench.c                    | 9 +++++++++
 src/bin/pgbench/pgbench.h                    | 3 ++-
 src/bin/pgbench/t/001_pgbench_with_server.pl | 7 ++++++-
 5 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/doc/src/sgml/ref/pgbench.sgml b/doc/src/sgml/ref/pgbench.sgml
index e509e6c7f62..e12a149c5bb 100644
--- a/doc/src/sgml/ref/pgbench.sgml
+++ b/doc/src/sgml/ref/pgbench.sgml
@@ -1022,6 +1022,13 @@ pgbench <optional> <replaceable>options</replaceable> </optional> <replaceable>d
        <entry><literal>sqrt(2.0)</literal></entry>
        <entry><literal>1.414213562</literal></entry>
       </row>
+      <row>
+       <entry><literal><function>pow(<replaceable>x</replaceable>, <replaceable>y</replaceable>)</function></literal></entry>
+       <entry>double if <replaceable>x</replaceable> or <replaceable>y</replaceable> are doubles, else integer</entry>
+       <entry>Numeric exponentiation</entry>
+       <entry><literal>pow(2.0, 10)</literal></entry>
+       <entry><literal>1024.0/<literal></entry>
+      </row>
      </tbody>
      </tgroup>
    </table>
diff --git a/src/bin/pgbench/exprparse.y b/src/bin/pgbench/exprparse.y
index b3a2d9bfd37..4db3b215abf 100644
--- a/src/bin/pgbench/exprparse.y
+++ b/src/bin/pgbench/exprparse.y
@@ -191,6 +191,9 @@ static const struct
 	{
 		"random_exponential", 3, PGBENCH_RANDOM_EXPONENTIAL
 	},
+	{
+		"pow", 2, PGBENCH_POW
+	},
 	/* keep as last array element */
 	{
 		NULL, 0, 0
diff --git a/src/bin/pgbench/pgbench.c b/src/bin/pgbench/pgbench.c
index 5d8a01c72cf..a3aef108f84 100644
--- a/src/bin/pgbench/pgbench.c
+++ b/src/bin/pgbench/pgbench.c
@@ -1346,6 +1346,7 @@ evalFunc(TState *thread, CState *st,
 		case PGBENCH_MUL:
 		case PGBENCH_DIV:
 		case PGBENCH_MOD:
+		case PGBENCH_POW:
 			{
 				PgBenchValue *lval = &vargs[0],
 						   *rval = &vargs[1];
@@ -1381,6 +1382,10 @@ evalFunc(TState *thread, CState *st,
 							setDoubleValue(retval, ld / rd);
 							return true;

+						case PGBENCH_POW:
+							setDoubleValue(retval, pow(ld, rd));
+							return true;
+
 						default:
 							/* cannot get here */
 							Assert(0);
@@ -1442,6 +1447,10 @@ evalFunc(TState *thread, CState *st,

 							return true;

+						case PGBENCH_POW:
+							setIntValue(retval, pow(li, ri));
+							return true;
+
 						default:
 							/* cannot get here */
 							Assert(0);
diff --git a/src/bin/pgbench/pgbench.h b/src/bin/pgbench/pgbench.h
index fd428af274f..e0132b5fcf6 100644
--- a/src/bin/pgbench/pgbench.h
+++ b/src/bin/pgbench/pgbench.h
@@ -75,7 +75,8 @@ typedef enum PgBenchFunction
 	PGBENCH_SQRT,
 	PGBENCH_RANDOM,
 	PGBENCH_RANDOM_GAUSSIAN,
-	PGBENCH_RANDOM_EXPONENTIAL
+	PGBENCH_RANDOM_EXPONENTIAL,
+	PGBENCH_POW
 } PgBenchFunction;

 typedef struct PgBenchExpr PgBenchExpr;
diff --git a/src/bin/pgbench/t/001_pgbench_with_server.pl b/src/bin/pgbench/t/001_pgbench_with_server.pl
index 11bc0fecfef..601c7ee0e4d 100644
--- a/src/bin/pgbench/t/001_pgbench_with_server.pl
+++ b/src/bin/pgbench/t/001_pgbench_with_server.pl
@@ -218,7 +218,9 @@ sub pgbench
 		qr{command=18.: double 18\b},
 		qr{command=19.: double 19\b},
 		qr{command=20.: double 20\b},
-		qr{command=21.: int 9223372036854775807\b}, ],
+		qr{command=21.: int 9223372036854775807\b},
+		qr{command=23.: int -27\b},
+		qr{command=24.: double 1024\b}, ],
 	'pgbench expressions',
 	{   '001_pgbench_expressions' => q{-- integer functions
 \set i1 debug(random(1, 100))
@@ -248,6 +250,9 @@ sub pgbench
 \set maxint debug(:minint - 1)
 -- reset a variable
 \set i1 0
+--- pow() operator
+\set poweri debug(pow(-3,3))
+\set powerd debug(pow(2.0,10))
 } });

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