On Mon, Sep 26, 2016 at 1:05 PM, Etsuro Fujita <fujita.ets...@lab.ntt.co.jp> wrote: > On 2016/09/15 15:29, Ashutosh Bapat wrote: >> >> On Wed, Sep 14, 2016 at 8:52 PM, Robert Haas <robertmh...@gmail.com> >> wrote: > > >>> I'm not sure why it wouldn't work >>> to just use the lowest RTI involved in the join, though; the others >>> won't appear anywhere else at that query level. > > >> So +1 for >> using the smallest RTI to indicate a subquery. > > > +1 for the general idea. > > ISTM that the use of the same RTI for subqueries in multi-levels in a remote > SQL makes the SQL a bit difficult to read. How about using the position of > the join rel in join_rel_list, (more precisely, the position plus > list_length(root->parse->rtable)), instead? > We switch to hash table to maintain the join RelOptInfos when the number of joins grows larger, where the position won't make much sense. We might differentiate between a base relation alias and subquery alias by using different prefixes like "r" and "s" resp.
-- Best Wishes, Ashutosh Bapat EnterpriseDB Corporation The Postgres Database Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
