On Tue, Jun 30, 2009 at 2:00 AM, Waldemar Bergstreiser<littlesuspe...@web.de> wrote: >> On Mon, Jun 29, 2009 at 2:08 PM, littlesuspense<littlesuspe...@web.de> wrote: >> > Hi Volk, >> > >> Note that the word outer is just noise in pgsql, i.e. it's not needed. >> What you've got are left outer, right outer, and full outer joins. >> All can be called just left, right, or full joins. Note that inner >> joins are just called joins. >> >> > select * from a, outer b where a.id = b.id; >> >> select * from a full join b on (a.id=b.id) where ... >> select * from a left join b on (a.id=b.id) where ... >> select * from a join b on (a.id=b.id) where ... > > this is only a simple case, but outer can make syntax more clean in > complicated joins. > Just try to rewrite query below with left outter joins. I had not found any > compact syntax. > > -- c *= b *= a =* d =* f > select * from a, outer( b, outer c), outer (d, outer f ) > where a.b_id = b.id and b.c_id = c.id and a.d_id = d.id and d.f_id = f.id;
from a full join b on (a.id=b.id) full join c on (b.id=c.id) full join d and so on. Doesn't seem any lestt compact or readable to me. >> What you get with postgresql is mostly ANSI standard stuff, which >> left/right/full outer and inner joins are. >> > And I like that, but each SQL RDMS system and each SQL dialect de facto > provide also a lot of standard extensions. So the RDMS user has a choice, to > use such extensions or not. And I think postgres can only win if we it have > more and very sane extensions. If the standard SQL syntax does the job, I see no reason to include non-standard syntax from other dbs unless they're obviously cleaner and simpler, and I really don't see that here. Every thing you add to the query planner / executor costs something in planning and / or execution times. Further, most database engines now support sql standard join syntax, so there's no great reason to support it for compatibility reasons. -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
