On Wed, Nov 4, 2009 at 2:11 PM, Tom Lane <t...@sss.pgh.pa.us> wrote: > Richard Broersma <richard.broer...@gmail.com> writes: >> Can anyone one explain why a "WITH RECURSIVE" query has the same >> results regardless whether UNION or UNION ALL is specified? > > Well, if the rows are all different anyway, UNION isn't going to > eliminate any ...
Actually I'm still confused. I must me missing something. When I manually following the directions of: http://www.postgresql.org/docs/8.4/interactive/queries-with.html I get the following when I try: WITH RECURSIVE t(n) AS ( VALUES (1) UNION ALL SELECT n+1 FROM t WHERE n < 100 ) SELECT sum(n) FROM t; (1) --initial non-recursive working table (1) UA (2) = (1,2) --new(1) working table (1,2) UA (2,3) = (1,2,2,3) --new(2) working table (1,2,2,3) UA (2,3,3,4) = (1,2,2,2,3,3,3,4) --new(3) working table -- Regards, Richard Broersma Jr. Visit the Los Angeles PostgreSQL Users Group (LAPUG) http://pugs.postgresql.org/lapug -- Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-sql
