Hi 2012/8/8 Jeff Janes <jeff.janes@xxxxxxxxx>: > On Tue, Aug 7, 2012 at 5:07 PM, Stefan Keller <sfkeller@xxxxxxxxx> wrote: >> Hi Craig >> >> Clever proposal! >> I slightly tried to adapt it to the hstore involved. >> Now I'm having a weird problem that PG says that "relation 'p' does not exist". >> Why does PG recognize table b in the subquery but not table p? >> Any ideas? > > I don't think it does recognize b, either. It just fell over on p > before it had a chance to fall over on b. No, the b get's recognized. See my original query. That's a strange behaviour of the SQL parser which I can't understand. > I think you have to use WITH if you want to reference the same > subquery in multiple FROMs. I'll try that with CTE too. > Another approach would be to add explicit conditions for there being > at least 1 school and 1 pharmacy within distance. There can't be >1 > unless there is >=1, but the join possibilities for >=1 (i.e. "where > exists" rather than "where (select count(*)...)>1" ) are much more > attractive than the ones for >1. > > Cheers, > > Jeff You mean, first doing a select on existence and then apply the count condition later? Stefan -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
