Dimitri Fontaine <dimitri@2ndQuadrant.fr> writes:
> Tom Lane <tgl@sss.pgh.pa.us> writes:
>>> [ about omitting rows for which there is no update path ]
>> Yeah, possibly. I'm a bit concerned about cases where the author meant
>> to provide an update path and forgot: it would be fairly obvious in this
>> representation but maybe you could keep making the same oversight if the
>> row's not there at all. Also, it's easy enough to write "where path is
>> not null" if you want to filter the rows that way.
> I would expect the author to check with something like
> WHERE installed = '1.0' and available = '1.2'
I don't really think that's a behavior we want to encourage. ISTM the
cases that are going to be trouble are paths you failed to think about,
and therefore what you want to do is look over the whole output set to
see if there are any surprising paths...
regards, tom lane