Re: [SQL] plpgsql doesn't coerce boolean expressions to boolean

Manfred Koizar <mkoi-pg@aon.at> writes:
> On Mon, 08 Sep 2003 11:40:32 -0400, Tom Lane <tgl@sss.pgh.pa.us>
> wrote:
>> 4. Use the parser's coerce_to_boolean procedure, so that nonbooleans
>> will be accepted in exactly the same cases where they'd be accepted
>> in a boolean-requiring SQL construct (such as CASE).  (By default,
>> none are, so this isn't really different from #2.  But people could
>> create casts to boolean to override this behavior in a controlled
>> fashion.)

> I vote for 4.

I'm willing to do that.

> And - being fully aware of similar proposals having
> failed miserably - I propose to proceed as follows:

> If the current behaviour is considered a bug, let i=4, else let i=5.

> In 7.i:  Create a new GUC variable "plpgsql_strict_boolean" (silly
> name, I know) in the "VERSION/PLATFORM COMPATIBILITY" section of
> postgresql.conf.  Make the new behaviour dependent on this variable.
> Default plpgsql_strict_boolean to false.  Place a warning into the
> release notes and maybe into the plpgsql documentation.

> In 7.j, j>i:  Change the default value of plpgsql_strict_boolean to
> true.  Issue WARNINGs or NOTICEs as appropriate.  Update
> documentation.

> In 7.k, k>j:  Remove old behaviour and GUC variable.  Update
> documentation.

I'm not willing to do that much work for what is, in the greater scheme
of things, a tiny change.  If we did that for every user-visible change,
our rate of forward progress would be a mere fraction of what it is.
        regards, tom lane