Hello Tom,
Monday, January 14, 2019, 6:15:31 PM, you wrote:
> =?utf-8?q?PG_Doc_comments_form?= <noreply@postgresql.org> writes:
>> https://www.postgresql.org/docs/current/queries-table-expressions.html#QUERIES-LATERAL
>>> The resulting row(s) are joined as usual with the rows they were computed
>>> from.
>> Here is not so clear what 'joined as usual' mean.
> Why not?
Advanced users may understand that, but from my beginner point of view
this is not. I do not understand that sentence until read whole text
and about LEFT JOIN LATERAL. Even now 'usual' may mean:
CROSS/RIGHT/FULL??
>> Probably DOC should explicitly say that if LATERAL function return empty set
>> then current row is excluded from result set
> That would be wrong for "LEFT JOIN LATERAL ...", so it does not seem
> like an improvement.
LATERAL != LEFT JOIN LATERAL
it would be more clear if DOC will be more explicit.
> regards, tom lane
--
Best regards,
Eugen Konkov