Re: DOC not so clear

Hello Tom,

Monday, January 14, 2019, 6:15:31 PM, you wrote:

> =?utf-8?q?PG_Doc_comments_form?= <noreply(at)postgresql(dot)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