From e482dcb0a438dfa1fcb2cb792730c00db337a834 Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Sat, 13 Oct 2001 23:32:34 +0000
Subject: [PATCH] Make selectivity routines cope gracefully with NaNs,
infinities, and NUMERIC values that are out of the range of 'double'. Per
trouble report from Mike Quinn.
---
src/backend/utils/adt/numeric.c | 31 ++++++++++++++++++++++++++++++-
src/backend/utils/adt/selfuncs.c | 28 +++++++++++++++++++++-------
src/include/utils/builtins.h | 3 ++-
3 files changed, 53 insertions(+), 9 deletions(-)
diff --git a/src/backend/utils/adt/numeric.c b/src/backend/utils/adt/numeric.c
index 797586018d0..5160f690c1e 100644
--- a/src/backend/utils/adt/numeric.c
+++ b/src/backend/utils/adt/numeric.c
@@ -5,7 +5,7 @@
*
* 1998 Jan Wieck
*
- * $Header: /cvsroot/pgsql/src/backend/utils/adt/numeric.c,v 1.44 2001/10/03 05:29:24 thomas Exp $
+ * $Header: /cvsroot/pgsql/src/backend/utils/adt/numeric.c,v 1.45 2001/10/13 23:32:33 tgl Exp $
*
* ----------
*/
@@ -1663,6 +1663,35 @@ numeric_float8(PG_FUNCTION_ARGS)
}
+/* Convert numeric to float8; if out of range, return +/- HUGE_VAL */
+Datum
+numeric_float8_no_overflow(PG_FUNCTION_ARGS)
+{
+ Numeric num = PG_GETARG_NUMERIC(0);
+ char *tmp;
+ double val;
+ char *endptr;
+
+ if (NUMERIC_IS_NAN(num))
+ PG_RETURN_FLOAT8(NAN);
+
+ tmp = DatumGetCString(DirectFunctionCall1(numeric_out,
+ NumericGetDatum(num)));
+
+ /* unlike float8in, we ignore ERANGE from strtod */
+ val = strtod(tmp, &endptr);
+ if (*endptr != '\0')
+ {
+ /* shouldn't happen ... */
+ elog(ERROR, "Bad float8 input format '%s'", tmp);
+ }
+
+ pfree(tmp);
+
+ PG_RETURN_FLOAT8(val);
+}
+
+
Datum
float4_numeric(PG_FUNCTION_ARGS)
{
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index 57c7e854614..306758ff77e 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -15,7 +15,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/utils/adt/selfuncs.c,v 1.98 2001/10/03 18:25:59 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/utils/adt/selfuncs.c,v 1.99 2001/10/13 23:32:33 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -581,7 +581,18 @@ scalarineqsel(Query *root, Oid operator, bool isgt,
else if (val >= high)
binfrac = 1.0;
else
+ {
binfrac = (val - low) / (high - low);
+ /*
+ * Watch out for the possibility that we got a NaN
+ * or Infinity from the division. This can happen
+ * despite the previous checks, if for example
+ * "low" is -Infinity.
+ */
+ if (isnan(binfrac) ||
+ binfrac < 0.0 || binfrac > 1.0)
+ binfrac = 0.5;
+ }
}
else
{
@@ -1665,8 +1676,8 @@ icnlikejoinsel(PG_FUNCTION_ARGS)
* subroutines in pg_type.
*
* All numeric datatypes are simply converted to their equivalent
- * "double" values. XXX what about NUMERIC values that are outside
- * the range of "double"?
+ * "double" values. (NUMERIC values that are outside the range of "double"
+ * are clamped to +/- HUGE_VAL.)
*
* String datatypes are converted by convert_string_to_scalar(),
* which is explained below. The reason why this routine deals with
@@ -1677,8 +1688,9 @@ icnlikejoinsel(PG_FUNCTION_ARGS)
*
* The several datatypes representing absolute times are all converted
* to Timestamp, which is actually a double, and then we just use that
- * double value. Note this will give bad results for the various "special"
- * values of Timestamp --- what can we do with those?
+ * double value. Note this will give correct results even for the "special"
+ * values of Timestamp, since those are chosen to compare correctly;
+ * see timestamp_cmp.
*
* The several datatypes representing relative times (intervals) are all
* converted to measurements expressed in seconds.
@@ -1793,8 +1805,10 @@ convert_numeric_to_scalar(Datum value, Oid typid)
case FLOAT8OID:
return (double) DatumGetFloat8(value);
case NUMERICOID:
- return (double) DatumGetFloat8(DirectFunctionCall1(numeric_float8,
- value));
+ /* Note: out-of-range values will be clamped to +-HUGE_VAL */
+ return (double)
+ DatumGetFloat8(DirectFunctionCall1(numeric_float8_no_overflow,
+ value));
case OIDOID:
case REGPROCOID:
/* we can treat OIDs as integers... */
diff --git a/src/include/utils/builtins.h b/src/include/utils/builtins.h
index 12792f15288..36d85aa0421 100644
--- a/src/include/utils/builtins.h
+++ b/src/include/utils/builtins.h
@@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $Id: builtins.h,v 1.167 2001/10/13 16:34:08 tgl Exp $
+ * $Id: builtins.h,v 1.168 2001/10/13 23:32:34 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -553,6 +553,7 @@ extern Datum int2_numeric(PG_FUNCTION_ARGS);
extern Datum numeric_int2(PG_FUNCTION_ARGS);
extern Datum float8_numeric(PG_FUNCTION_ARGS);
extern Datum numeric_float8(PG_FUNCTION_ARGS);
+extern Datum numeric_float8_no_overflow(PG_FUNCTION_ARGS);
extern Datum float4_numeric(PG_FUNCTION_ARGS);
extern Datum numeric_float4(PG_FUNCTION_ARGS);
extern Datum numeric_accum(PG_FUNCTION_ARGS);
--
GitLab