fasternumeric_20121112_v2.patch

diff --git a/src/backend/utils/adt/numeric.c b/src/backend/utils/adt/numeric.c
index 68c1f1d..fcff325 100644
--- a/src/backend/utils/adt/numeric.c
+++ b/src/backend/utils/adt/numeric.c
@@ -367,6 +367,7 @@ static void zero_var(NumericVar *var);
 static const char *set_var_from_str(const char *str, const char *cp,
 				 NumericVar *dest);
 static void set_var_from_num(Numeric value, NumericVar *dest);
+static void set_var_from_num_nocopy(Numeric num, NumericVar *dest);
 static void set_var_from_var(NumericVar *value, NumericVar *dest);
 static char *get_str_from_var(NumericVar *var, int dscale);
 static char *get_str_from_var_sci(NumericVar *var, int rscale);
@@ -617,11 +618,10 @@ numeric_out_sci(Numeric num, int scale)
 		return pstrdup("NaN");
 
 	init_var(&x);
-	set_var_from_num(num, &x);
+	set_var_from_num_nocopy(num, &x);
 
 	str = get_str_from_var_sci(&x, scale);
 
-	free_var(&x);
 	return str;
 }
 
@@ -696,7 +696,7 @@ numeric_send(PG_FUNCTION_ARGS)
 	int			i;
 
 	init_var(&x);
-	set_var_from_num(num, &x);
+	set_var_from_num_nocopy(num, &x);
 
 	pq_begintypsend(&buf);
 
@@ -707,8 +707,6 @@ numeric_send(PG_FUNCTION_ARGS)
 	for (i = 0; i < x.ndigits; i++)
 		pq_sendint(&buf, x.digits[i], sizeof(NumericDigit));
 
-	free_var(&x);
-
 	PG_RETURN_BYTEA_P(pq_endtypsend(&buf));
 }
 
@@ -1577,15 +1575,13 @@ numeric_add(PG_FUNCTION_ARGS)
 	init_var(&arg2);
 	init_var(&result);
 
-	set_var_from_num(num1, &arg1);
-	set_var_from_num(num2, &arg2);
+	set_var_from_num_nocopy(num1, &arg1);
+	set_var_from_num_nocopy(num2, &arg2);
 
 	add_var(&arg1, &arg2, &result);
 
 	res = make_result(&result);
 
-	free_var(&arg1);
-	free_var(&arg2);
 	free_var(&result);
 
 	PG_RETURN_NUMERIC(res);
@@ -1620,15 +1616,13 @@ numeric_sub(PG_FUNCTION_ARGS)
 	init_var(&arg2);
 	init_var(&result);
 
-	set_var_from_num(num1, &arg1);
-	set_var_from_num(num2, &arg2);
+	set_var_from_num_nocopy(num1, &arg1);
+	set_var_from_num_nocopy(num2, &arg2);
 
 	sub_var(&arg1, &arg2, &result);
 
 	res = make_result(&result);
 
-	free_var(&arg1);
-	free_var(&arg2);
 	free_var(&result);
 
 	PG_RETURN_NUMERIC(res);
@@ -1667,15 +1661,13 @@ numeric_mul(PG_FUNCTION_ARGS)
 	init_var(&arg2);
 	init_var(&result);
 
-	set_var_from_num(num1, &arg1);
-	set_var_from_num(num2, &arg2);
+	set_var_from_num_nocopy(num1, &arg1);
+	set_var_from_num_nocopy(num2, &arg2);
 
 	mul_var(&arg1, &arg2, &result, arg1.dscale + arg2.dscale);
 
 	res = make_result(&result);
 
-	free_var(&arg1);
-	free_var(&arg2);
 	free_var(&result);
 
 	PG_RETURN_NUMERIC(res);
@@ -1711,8 +1703,8 @@ numeric_div(PG_FUNCTION_ARGS)
 	init_var(&arg2);
 	init_var(&result);
 
-	set_var_from_num(num1, &arg1);
-	set_var_from_num(num2, &arg2);
+	set_var_from_num_nocopy(num1, &arg1);
+	set_var_from_num_nocopy(num2, &arg2);
 
 	/*
 	 * Select scale for division result
@@ -1726,8 +1718,6 @@ numeric_div(PG_FUNCTION_ARGS)
 
 	res = make_result(&result);
 
-	free_var(&arg1);
-	free_var(&arg2);
 	free_var(&result);
 
 	PG_RETURN_NUMERIC(res);
@@ -1762,8 +1752,8 @@ numeric_div_trunc(PG_FUNCTION_ARGS)
 	init_var(&arg2);
 	init_var(&result);
 
-	set_var_from_num(num1, &arg1);
-	set_var_from_num(num2, &arg2);
+	set_var_from_num_nocopy(num1, &arg1);
+	set_var_from_num_nocopy(num2, &arg2);
 
 	/*
 	 * Do the divide and return the result
@@ -1772,8 +1762,6 @@ numeric_div_trunc(PG_FUNCTION_ARGS)
 
 	res = make_result(&result);
 
-	free_var(&arg1);
-	free_var(&arg2);
 	free_var(&result);
 
 	PG_RETURN_NUMERIC(res);
@@ -1802,15 +1790,13 @@ numeric_mod(PG_FUNCTION_ARGS)
 	init_var(&arg2);
 	init_var(&result);
 
-	set_var_from_num(num1, &arg1);
-	set_var_from_num(num2, &arg2);
+	set_var_from_num_nocopy(num1, &arg1);
+	set_var_from_num_nocopy(num2, &arg2);
 
 	mod_var(&arg1, &arg2, &result);
 
 	res = make_result(&result);
 
-	free_var(&result);
-	free_var(&arg2);
 	free_var(&arg1);
 
 	PG_RETURN_NUMERIC(res);
@@ -1980,7 +1966,7 @@ numeric_sqrt(PG_FUNCTION_ARGS)
 	init_var(&arg);
 	init_var(&result);
 
-	set_var_from_num(num, &arg);
+	set_var_from_num_nocopy(num, &arg);
 
 	/* Assume the input was normalized, so arg.weight is accurate */
 	sweight = (arg.weight + 1) * DEC_DIGITS / 2 - 1;
@@ -1998,7 +1984,6 @@ numeric_sqrt(PG_FUNCTION_ARGS)
 	res = make_result(&result);
 
 	free_var(&result);
-	free_var(&arg);
 
 	PG_RETURN_NUMERIC(res);
 }
@@ -2033,7 +2018,7 @@ numeric_exp(PG_FUNCTION_ARGS)
 	init_var(&arg);
 	init_var(&result);
 
-	set_var_from_num(num, &arg);
+	set_var_from_num_nocopy(num, &arg);
 
 	/* convert input to float8, ignoring overflow */
 	val = numericvar_to_double_no_overflow(&arg);
@@ -2061,7 +2046,6 @@ numeric_exp(PG_FUNCTION_ARGS)
 	res = make_result(&result);
 
 	free_var(&result);
-	free_var(&arg);
 
 	PG_RETURN_NUMERIC(res);
 }
@@ -2091,7 +2075,7 @@ numeric_ln(PG_FUNCTION_ARGS)
 	init_var(&arg);
 	init_var(&result);
 
-	set_var_from_num(num, &arg);
+	set_var_from_num_nocopy(num, &arg);
 
 	/* Approx decimal digits before decimal point */
 	dec_digits = (arg.weight + 1) * DEC_DIGITS;
@@ -2112,7 +2096,6 @@ numeric_ln(PG_FUNCTION_ARGS)
 	res = make_result(&result);
 
 	free_var(&result);
-	free_var(&arg);
 
 	PG_RETURN_NUMERIC(res);
 }
@@ -2146,8 +2129,8 @@ numeric_log(PG_FUNCTION_ARGS)
 	init_var(&arg2);
 	init_var(&result);
 
-	set_var_from_num(num1, &arg1);
-	set_var_from_num(num2, &arg2);
+	set_var_from_num_nocopy(num1, &arg1);
+	set_var_from_num_nocopy(num2, &arg2);
 
 	/*
 	 * Call log_var() to compute and return the result; note it handles scale
@@ -2158,8 +2141,6 @@ numeric_log(PG_FUNCTION_ARGS)
 	res = make_result(&result);
 
 	free_var(&result);
-	free_var(&arg2);
-	free_var(&arg1);
 
 	PG_RETURN_NUMERIC(res);
 }
@@ -2195,8 +2176,8 @@ numeric_power(PG_FUNCTION_ARGS)
 	init_var(&arg2_trunc);
 	init_var(&result);
 
-	set_var_from_num(num1, &arg1);
-	set_var_from_num(num2, &arg2);
+	set_var_from_num_nocopy(num1, &arg1);
+	set_var_from_num_nocopy(num2, &arg2);
 	set_var_from_var(&arg2, &arg2_trunc);
 
 	trunc_var(&arg2_trunc, 0);
@@ -2227,9 +2208,7 @@ numeric_power(PG_FUNCTION_ARGS)
 	res = make_result(&result);
 
 	free_var(&result);
-	free_var(&arg2);
 	free_var(&arg2_trunc);
-	free_var(&arg1);
 
 	PG_RETURN_NUMERIC(res);
 }
@@ -2277,9 +2256,8 @@ numeric_int4(PG_FUNCTION_ARGS)
 
 	/* Convert to variable format, then convert to int4 */
 	init_var(&x);
-	set_var_from_num(num, &x);
+	set_var_from_num_nocopy(num, &x);
 	result = numericvar_to_int4(&x);
-	free_var(&x);
 	PG_RETURN_INT32(result);
 }
 
@@ -2400,8 +2378,6 @@ numeric_int2(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("smallint out of range")));
 
-	free_var(&x);
-
 	/* Down-convert to int2 */
 	result = (int16) val;
 
@@ -2411,6 +2387,8 @@ numeric_int2(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("smallint out of range")));
 
+	free_var(&x);
+
 	PG_RETURN_INT16(result);
 }
 
@@ -2764,7 +2742,7 @@ numeric_stddev_internal(ArrayType *transarray,
 		return make_result(&const_nan);
 
 	init_var(&vN);
-	set_var_from_num(N, &vN);
+	set_var_from_num_nocopy(N, &vN);
 
 	/*
 	 * Sample stddev and variance are undefined when N <= 1; population stddev
@@ -2777,7 +2755,6 @@ numeric_stddev_internal(ArrayType *transarray,
 
 	if (cmp_var(&vN, comp) <= 0)
 	{
-		free_var(&vN);
 		*is_null = true;
 		return NULL;
 	}
@@ -2786,7 +2763,7 @@ numeric_stddev_internal(ArrayType *transarray,
 	sub_var(&vN, &const_one, &vNminus1);
 
 	init_var(&vsumX);
-	set_var_from_num(sumX, &vsumX);
+	set_var_from_num_nocopy(sumX, &vsumX);
 	init_var(&vsumX2);
 	set_var_from_num(sumX2, &vsumX2);
 
@@ -2816,9 +2793,7 @@ numeric_stddev_internal(ArrayType *transarray,
 		res = make_result(&vsumX);
 	}
 
-	free_var(&vN);
 	free_var(&vNminus1);
-	free_var(&vsumX);
 	free_var(&vsumX2);
 
 	return res;
@@ -3448,6 +3423,21 @@ set_var_from_num(Numeric num, NumericVar *dest)
 	memcpy(dest->digits, NUMERIC_DIGITS(num), ndigits * sizeof(NumericDigit));
 }
 
+/*
+ * set_var_from_num_nocopy() -
+ *
+ *	Convert the packed db format into a variable - without copying digits
+ */
+static void
+set_var_from_num_nocopy(Numeric num, NumericVar *dest)
+{
+	dest->ndigits = NUMERIC_NDIGITS(num);
+	dest->weight = NUMERIC_WEIGHT(num);
+	dest->sign = NUMERIC_SIGN(num);
+	dest->dscale = NUMERIC_DSCALE(num);
+	dest->digits = NUMERIC_DIGITS(num);
+}
+
 
 /*
  * set_var_from_var() -