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authorTom Lane <tgl@sss.pgh.pa.us>2001-10-13 23:32:34 +0000
committerTom Lane <tgl@sss.pgh.pa.us>2001-10-13 23:32:34 +0000
commite482dcb0a438dfa1fcb2cb792730c00db337a834 (patch)
tree6474f00c50a7ccd98906635bd4ceabe8a5f909ab /src/backend/utils/adt/selfuncs.c
parentd1c6983899df5b154c203c6f1ddf56914c0bbb30 (diff)
downloadpostgresql-e482dcb0a438dfa1fcb2cb792730c00db337a834.tar.gz
postgresql-e482dcb0a438dfa1fcb2cb792730c00db337a834.zip
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.
Diffstat (limited to 'src/backend/utils/adt/selfuncs.c')
-rw-r--r--src/backend/utils/adt/selfuncs.c28
1 files changed, 21 insertions, 7 deletions
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... */