Обсуждение: Part 2 of "Intentional, or a bug"....

Hi again.

First of all, tank you for the immediate and precise answers.

My solution to the problem was the following. However, I found
that to be quite slow. I would like to ask if one can suggest me
how to optimize this, because I need this regularly.

CREATE FUNCTION gyegyenlo(text, text) RETURNS boolean AS ' SELECT CASE WHEN $1 is null and $2 is null THEN true
                        ELSE ($1) = ($2)      END;
 
' LANGUAGE 'sql';

CREATE OPERATOR ~= ( leftarg = text, rightarg = text, procedure = gyegyenlo, commutator = ~=
);

After these I use ~= if I need lines with NULLs in both to be selected.

The only problem is that it makes the query very slow. Does anyone
knows how to optimize this?

Thanks,
Baldvin

Kovacs Baldvin <kb136@hszk.bme.hu> writes:
> After these I use ~= if I need lines with NULLs in both to be selected.

Perhaps you should reconsider your data model.  You seem to be treating
NULL as if it were a real value, which is something that SQL discourages
rather strongly...
        regards, tom lane

> > After these I use ~= if I need lines with NULLs in both to be selected.
>
> Perhaps you should reconsider your data model.  You seem to be treating

The given column is a date type column, with some records where
"date is not given". This "not given" is represented by NULL.
I saw it more elegant than assigning a date in the very past for
"not given", or using a boolean column called "date given".

After all, I consider using the additional boolean column.

Bye,
Baldvin