Re: lateral function as a subquery - WIP patch - Mailing list pgsql-hackers

From Antonin Houska
Subject Re: lateral function as a subquery - WIP patch
Date
Msg-id 4F5B8974.9090301@gmail.com
Whole thread Raw
In response to Re: lateral function as a subquery - WIP patch  (Tom Lane <tgl@sss.pgh.pa.us>)
List 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.


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