diff --git a/doc/src/sgml/ref/pgbench.sgml b/doc/src/sgml/ref/pgbench.sgml
index a6c69ff344d..e6c7c94fe25 100644
--- a/doc/src/sgml/ref/pgbench.sgml
+++ b/doc/src/sgml/ref/pgbench.sgml
@@ -935,14 +935,15 @@ pgbench <optional> <replaceable>options</> </optional> <replaceable>dbname</>
       <row>
        <entry><literal><function>abs(<replaceable>a</>)</></></>
        <entry>same as <replaceable>a</></>
-       <entry>integer or double absolute value</>
+       <entry>absolute value</>
        <entry><literal>abs(-17)</></>
        <entry><literal>17</></>
       </row>
       <row>
        <entry><literal><function>debug(<replaceable>a</>)</></></>
        <entry>same as <replaceable>a</> </>
-       <entry>print to <systemitem>stderr</systemitem> the given argument</>
+       <entry>print <replaceable>a</> to <systemitem>stderr</systemitem>,
+        and return <replaceable>a</></>
        <entry><literal>debug(5432.1)</></>
        <entry><literal>5432.1</></>
       </row>
@@ -961,23 +962,23 @@ pgbench <optional> <replaceable>options</> </optional> <replaceable>dbname</>
        <entry><literal>9</></>
       </row>
       <row>
-       <entry><literal><function>max(<replaceable>i</> [, <replaceable>...</> ] )</></></>
-       <entry>integer</>
-       <entry>maximum value</>
-       <entry><literal>max(5, 4, 3, 2)</></>
+       <entry><literal><function>greatest(<replaceable>a</> [, <replaceable>...</> ] )</></></>
+       <entry>double if any <replaceable>a</> is double, else integer</>
+       <entry>largest value among arguments</>
+       <entry><literal>greatest(5, 4, 3, 2)</></>
        <entry><literal>5</></>
       </row>
       <row>
-       <entry><literal><function>min(<replaceable>i</> [, <replaceable>...</> ] )</></></>
-       <entry>integer</>
-       <entry>minimum value</>
-       <entry><literal>min(5, 4, 3, 2)</></>
-       <entry><literal>2</></>
+       <entry><literal><function>least(<replaceable>a</> [, <replaceable>...</> ] )</></></>
+       <entry>double if any <replaceable>a</> is double, else integer</>
+       <entry>smallest value among arguments</>
+       <entry><literal>least(5, 4, 3, 2.1)</></>
+       <entry><literal>2.1</></>
       </row>
       <row>
        <entry><literal><function>pi()</></></>
        <entry>double</>
-       <entry>value of the PI constant</>
+       <entry>value of the constant PI</>
        <entry><literal>pi()</></>
        <entry><literal>3.14159265358979323846</></>
       </row>
diff --git a/src/bin/pgbench/exprparse.y b/src/bin/pgbench/exprparse.y
index 64c29dcfa7b..0cc665b75b4 100644
--- a/src/bin/pgbench/exprparse.y
+++ b/src/bin/pgbench/exprparse.y
@@ -131,7 +131,7 @@ make_op(yyscan_t yyscanner, const char *operator,
  * List of available functions:
  * - fname: function name
  * - nargs: number of arguments
- *			-1 is a special value for min & max meaning #args >= 1
+ *			-1 is a special value for least & greatest meaning #args >= 1
  * - tag: function identifier from PgBenchFunction enum
  */
 static const struct
@@ -162,10 +162,10 @@ static const struct
 		"abs", 1, PGBENCH_ABS
 	},
 	{
-		"min", -1, PGBENCH_MIN
+		"least", -1, PGBENCH_LEAST
 	},
 	{
-		"max", -1, PGBENCH_MAX
+		"greatest", -1, PGBENCH_GREATEST
 	},
 	{
 		"debug", 1, PGBENCH_DEBUG
@@ -274,7 +274,7 @@ make_func(yyscan_t yyscanner, int fnumber, PgBenchExprList *args)
 		expr_yyerror_more(yyscanner, "unexpected number of arguments",
 						  PGBENCH_FUNCTIONS[fnumber].fname);
 
-	/* check at least one arg for min & max */
+	/* check at least one arg for least & greatest */
 	if (PGBENCH_FUNCTIONS[fnumber].nargs == -1 &&
 		elist_length(args) == 0)
 		expr_yyerror_more(yyscanner, "at least one argument expected",
diff --git a/src/bin/pgbench/pgbench.c b/src/bin/pgbench/pgbench.c
index 076fbd38afe..2a9063a3453 100644
--- a/src/bin/pgbench/pgbench.c
+++ b/src/bin/pgbench/pgbench.c
@@ -1298,31 +1298,63 @@ evalFunc(TState *thread, CState *st,
 				return true;
 			}
 
-		/* variable number of int arguments */
-		case PGBENCH_MIN:
-		case PGBENCH_MAX:
+		/* variable number of arguments */
+		case PGBENCH_LEAST:
+		case PGBENCH_GREATEST:
 			{
-				int64		extremum;
+				bool		havedouble;
 				int			i;
+
 				Assert(nargs >= 1);
 
-				if (!coerceToInt(&vargs[0], &extremum))
-					return false;
-
-				for (i = 1; i < nargs; i++)
+				/* need double result if any input is double */
+				havedouble = false;
+				for (i = 0; i < nargs; i++)
 				{
-					int64		ival;
-
-					if (!coerceToInt(&vargs[i], &ival))
-						return false;
-
-					if (func == PGBENCH_MIN)
-						extremum = extremum < ival ? extremum : ival;
-					else if (func == PGBENCH_MAX)
-						extremum = extremum > ival ? extremum : ival;
+					if (vargs[i].type == PGBT_DOUBLE)
+					{
+						havedouble = true;
+						break;
+					}
 				}
+				if (havedouble)
+				{
+					double		extremum;
 
-				setIntValue(retval, extremum);
+					if (!coerceToDouble(&vargs[0], &extremum))
+						return false;
+					for (i = 1; i < nargs; i++)
+					{
+						double		dval;
+
+						if (!coerceToDouble(&vargs[i], &dval))
+							return false;
+						if (func == PGBENCH_LEAST)
+							extremum = Min(extremum, dval);
+						else
+							extremum = Max(extremum, dval);
+					}
+					setDoubleValue(retval, extremum);
+				}
+				else
+				{
+					int64		extremum;
+
+					if (!coerceToInt(&vargs[0], &extremum))
+						return false;
+					for (i = 1; i < nargs; i++)
+					{
+						int64		ival;
+
+						if (!coerceToInt(&vargs[i], &ival))
+							return false;
+						if (func == PGBENCH_LEAST)
+							extremum = Min(extremum, ival);
+						else
+							extremum = Max(extremum, ival);
+					}
+					setIntValue(retval, extremum);
+				}
 				return true;
 			}
 
diff --git a/src/bin/pgbench/pgbench.h b/src/bin/pgbench/pgbench.h
index 7dcb67f5203..58baad8ee67 100644
--- a/src/bin/pgbench/pgbench.h
+++ b/src/bin/pgbench/pgbench.h
@@ -67,8 +67,8 @@ typedef enum PgBenchFunction
 	PGBENCH_MOD,
 	PGBENCH_DEBUG,
 	PGBENCH_ABS,
-	PGBENCH_MIN,
-	PGBENCH_MAX,
+	PGBENCH_LEAST,
+	PGBENCH_GREATEST,
 	PGBENCH_INT,
 	PGBENCH_DOUBLE,
 	PGBENCH_PI,