From a6eecfe6637bdb0cbb02a9eda7b88d9c4325bb51 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 | 5 +++++
 5 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/doc/src/sgml/ref/pgbench.sgml b/doc/src/sgml/ref/pgbench.sgml
index 1f55967e40a60..2e913dfcfd6eb 100644
--- a/doc/src/sgml/ref/pgbench.sgml
+++ b/doc/src/sgml/ref/pgbench.sgml
@@ -1233,6 +1233,13 @@ 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 770be981f0654..290bca99d121d 100644
--- a/src/bin/pgbench/exprparse.y
+++ b/src/bin/pgbench/exprparse.y
@@ -334,6 +334,9 @@ static const struct
 	{
 		"!case_end", -2, PGBENCH_CASE
 	},
+	{
+		"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 add653bf90c30..b2bab9b8239ce 100644
--- a/src/bin/pgbench/pgbench.c
+++ b/src/bin/pgbench/pgbench.c
@@ -1474,6 +1474,7 @@ evalFunc(TState *thread, CState *st,
 		case PGBENCH_NE:
 		case PGBENCH_LE:
 		case PGBENCH_LT:
+		case PGBENCH_POW:
 			{
 				PgBenchValue *lval = &vargs[0],
 						   *rval = &vargs[1];
@@ -1525,6 +1526,10 @@ evalFunc(TState *thread, CState *st,
 							setBoolValue(retval, ld < rd);
 							return true;
 
+						case PGBENCH_POW:
+							setDoubleValue(retval, pow(ld, rd));
+							return true;
+
 						default:
 							/* cannot get here */
 							Assert(0);
@@ -1602,6 +1607,10 @@ 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 e1277a1dde678..9f26af92bf605 100644
--- a/src/bin/pgbench/pgbench.h
+++ b/src/bin/pgbench/pgbench.h
@@ -94,7 +94,8 @@ typedef enum PgBenchFunction
 	PGBENCH_LE,
 	PGBENCH_LT,
 	PGBENCH_IS,
-	PGBENCH_CASE
+	PGBENCH_CASE,
+	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 8e19bbd3f45ad..81b7ce4dfcccc 100644
--- a/src/bin/pgbench/t/001_pgbench_with_server.pl
+++ b/src/bin/pgbench/t/001_pgbench_with_server.pl
@@ -237,6 +237,8 @@ sub pgbench
 		qr{command=36.: int 36\b},
 		qr{command=37.: boolean true\b},
 		qr{command=38.: boolean true\b},
+		qr{command=44.: int -27\b},
+		qr{command=45.: double 1024\b},
 	],
 	'pgbench expressions',
 	{   '001_pgbench_expressions' => q{-- integer functions
@@ -299,6 +301,9 @@ sub pgbench
 \set v2 5432
 \set v3 -54.21E-2
 SELECT :v0, :v1, :v2, :v3;
+--- pow() operator
+\set poweri debug(pow(-3,3))
+\set powerd debug(pow(2.0,10))
 } });
 
 =head