Re: lateral function as a subquery - WIP patch

Antonin Houska <antonin.houska@gmail.com>

From: Antonin Houska <antonin.houska@gmail.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: pgsql-hackers@postgresql.org
Date: 2012-03-10T17:03:48Z
Lists: pgsql-hackers
On 03/10/2012 02:15 AM, Tom Lane wrote:
> Um ... how do you get the subquery result rows to join to only the
> correct rows of the other tables?
The subquery just restricts the set of rows that the function has to 
evaluate. The main query is supposed to perform the join.
I understand, such a join causes repeated scan of the function if the 
function is on the inner side.
> This looks like an unconstrained join
> to me, which is not what I believe the SQL spec for LATERAL to be,
o.k., then just forget about my proposal. Thanks for your comments anyway,

Tony H.