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Make selectivity routines cope gracefully with NaNs, infinities, and

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NUMERIC values that are out of the range of 'double'.  Per trouble
report from Mike Quinn.
This commit is contained in:
Tom Lane
2001-10-13 23:32:34 +00:00
parent d1c6983899
commit e482dcb0a4
3 changed files with 53 additions and 9 deletions
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28
src/backend/utils/adt/selfuncs.c
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@ -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... */