Peter Eisentraut writes:
> On 7/26/16 7:46 PM, Thomas Munro wrote:
>> By the way, our documentation says that NOT NULL constraints are
>> equivalent to CHECK (column_name IS NOT NULL). That is what the SQL
>> standard says, but in fact our NOT NULL constraints are equivalent to
>> CHECK (column_n
On 7/26/16 7:46 PM, Thomas Munro wrote:
> By the way, our documentation says that NOT NULL constraints are
> equivalent to CHECK (column_name IS NOT NULL). That is what the SQL
> standard says, but in fact our NOT NULL constraints are equivalent to
> CHECK (column_name IS DISTINCT FROM NULL). Sho
On Wed, Jul 27, 2016 at 7:35 AM, Tom Lane wrote:
> "David G. Johnston" writes:
>> The concept embodied by "NULL" in the operator "IS [NOT] NULL" is distinct
>> from the concept embodied by "NULL" in the operator "IS [NOT] DISTINCT
>> FROM".
>
>> In short, the former smooths out the differences be
"David G. Johnston" writes:
> The concept embodied by "NULL" in the operator "IS [NOT] NULL" is distinct
> from the concept embodied by "NULL" in the operator "IS [NOT] DISTINCT
> FROM".
> In short, the former smooths out the differences between composite and
> non-composite types while the later
On Tue, Jul 26, 2016 at 11:10 AM, Tom Lane wrote:
>
> 3. Andrew also revived the bug #7808 thread in which it was complained
> that ExecMakeTableFunctionResult should not fail on null results from
> functions returning SETOF composite. That's related only in that the
> proposed fix is to transla
Peter Eisentraut writes:
> On 7/22/16 7:01 PM, Andrew Gierth wrote:
>> In light of the fact that it is an endless cause of bugs both in pg and
>> potentially to applications, I propose that we cease attempting to
>> conform to the spec's definition of IS NULL in favour of the following
>> rules:
On Mon, Jul 25, 2016 at 8:28 PM, Peter Eisentraut
wrote:
> On 7/22/16 7:01 PM, Andrew Gierth wrote:
>> In light of the fact that it is an endless cause of bugs both in pg and
>> potentially to applications, I propose that we cease attempting to
>> conform to the spec's definition of IS NULL in fav
On 7/22/16 7:01 PM, Andrew Gierth wrote:
> In light of the fact that it is an endless cause of bugs both in pg and
> potentially to applications, I propose that we cease attempting to
> conform to the spec's definition of IS NULL in favour of the following
> rules:
I can't see how we would incompa
> "Andrew" == Andrew Gierth writes:
>>> Whole-row vars when constructed never contain the null value.
David> ...but what does this mean in end-user terms?
Andrew> It means for example that this query:
Andrew> select y from x left join y on (x.id=y.id) where y is null;
Andrew> woul
On 7/22/16 8:05 PM, David G. Johnston wrote:
I would expect that >95% of cases where someone has written (x IS NOT
NULL) for x being a composite type, it's actually a bug and that NOT (x
IS NULL) was intended.
Yeah, it would need to be targeted there. I agree with the numbers and
On Friday, July 22, 2016, Andrew Gierth wrote:
> > "David" == David G Johnston > writes:
>
> >> Prohibiting IS NOT NULL is not on the cards; it's very widely used.
>
> David> Yet changing how it behaves, invisibly, is?
>
> Did you mean prohibiting it only for composite-type args? It's obv
> "David" == David G Johnston writes:
>> Prohibiting IS NOT NULL is not on the cards; it's very widely used.
David> Yet changing how it behaves, invisibly, is?
Did you mean prohibiting it only for composite-type args? It's obviously
widely used for non-composite args.
I would expect tha
On Fri, Jul 22, 2016 at 8:04 PM, Andrew Gierth
wrote:
> > "David" == David G Johnston writes:
>
> >> 2. x IS NOT NULL if and only if NOT (x IS NULL)
>
> David> I would rather prohibit "IS NOT NULL" altogether. If one needs
> David> to test "NOT (x IS NULL)" they can write it that way.
> "David" == David G Johnston writes:
>> 1. x IS NULL is true if and only if x has the null value (isnull set).
David> I don't have a problem conforming to "ROW(NULL, NULL) IS NULL"
David> being true...if you somehow get a hold of something in that
David> form, which your others point
> "David" == David G Johnston writes:
>> 2. x IS NOT NULL if and only if NOT (x IS NULL)
David> I would rather prohibit "IS NOT NULL" altogether. If one needs
David> to test "NOT (x IS NULL)" they can write it that way.
Prohibiting IS NOT NULL is not on the cards; it's very widely us
On Fri, Jul 22, 2016 at 7:01 PM, Andrew Gierth
wrote:
> In light of the fact that it is an endless cause of bugs both in pg and
> potentially to applications, I propose that we cease attempting to
> conform to the spec's definition of IS NULL in favour of the following
> rules:
>
> 1. x IS NULL
In light of the fact that it is an endless cause of bugs both in pg and
potentially to applications, I propose that we cease attempting to
conform to the spec's definition of IS NULL in favour of the following
rules:
1. x IS NULL is true if and only if x has the null value (isnull set).
2. x IS
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