On Mon, Apr 11, 2022 at 7:20 AM Tom Lane <t...@sss.pgh.pa.us> wrote: > PALAYRET Jacques <jacques.palay...@meteo.fr> writes: > > For me, one of the two following things should be true : either the hint > (in case of a lateral error) is incomplete or the possibility of " cross > join lateral " should be removed.
> > The reason the hint is worded the way it is is a practical one: the other possibilities are not drop-in syntactic replacements. > > [...] > > SELECT * FROM t, sin(x); > SELECT * FROM t CROSS JOIN sin(x); > SELECT * FROM t JOIN sin(x) ON true; > SELECT * FROM t INNER JOIN sin(x) ON true; > SELECT * FROM t LEFT JOIN sin(x) ON true; > > > Another way to look at it is that there are only two allowed > semantic behaviors here: INNER and LEFT joins. The fact that > there's more than one way to spell an inner join is a historical > accident. > > Agreed on both points, and a hat-tip for the former. I did get somewhat annoyed previously that I had to write "on true" (I considered that a code smell) but decided it was a better option than both "t, six(x)" and "t cross join sin(x)" as I dislike the implicit format even more and the semantic mis-match with the cross join was unappealing as well. There really is no other option for a LEFT JOIN here so just the consistency with an INNER JOIN has now made writing "on true", at least for a lateral join, make sense to me. David J.
