Re: Proposal for Allow postgresql.conf values to be changed via SQL

On 12/03/2012 10:32 AM, Tom Lane wrote:
> Robert Haas <robertmhaas@gmail.com> writes:
>> On Mon, Dec 3, 2012 at 6:38 AM, Amit Kapila <amit.kapila@huawei.com> wrote:
>>> opt_persistent: PERSISTENT                                { $$ = TRUE; }
>>> | /*EMPTY*/                %prec Op        { $$ = FALSE; }
>>> ;
>>>
>>> I am not sure if there are any problems with above change.
>> We usually try to avoid operator precedence declarations.  They
>> sometimes have unforeseen consequences.
> Yes.  This is not an improvement over factoring out opt_persistent as
> I recommended previously.


This is by no means the first time this has come up. See 
<http://wiki.postgresql.org/wiki/Fixing_shift/reduce_conflicts_in_Bison>

cheers

andrew