I just bought a copy of SQL:2016-2, and it says nothing about Infinity
and NaN (or sNaN) for DECFLOAT (nor does it for double or float for that
matter).
I wonder if that means those values are not allowed and should instead
raise an exception when inserted, or the result of a calculation.
Mark
On 6-1-2018 17:30, Mark Rotteveel wrote:
If you have a decfloat column with a NaN (or sNaN) value, then selects
with a condition on that column will fail with the error below during
fetch.
====
*** IBPP::SQLException ***
Context: Statement::Fetch
Message: isc_dsql_fetch failed.
SQL Message : -901
Unsuccessful execution caused by system error that does not preclude
successful execution of subsequent statements
Engine Code : 335545141
Engine Message :
Decimal float invalid operation. An indeterminant error occurred during
an operation.
====
I would suggest that instead comparison with a NaN (or sNaN) would
always be false (even if the value compared to is NaN!), as is the case
in most programming languages when comparing double NaN.
And similar to NULL, checking for NaN would require something like IS
NaN (or maybe a ISNAN(..)). The only question is do we need to discern
between +/- NaN and +/- sNaN in these cases?
What do you think?
--
Mark Rotteveel
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