Thanks for the reply. I can do this at the higher level; but this antijoin thing is a small part of a bigger project. So I want to do it internally in one of the joins. Does anyone have experience in storing tupleslpts and comparing them ??
Gregory Stark wrote: > > "Suresh_" <[EMAIL PROTECTED]> writes: > >> I want to add an antijoin operator to PostgreSql. > > I think you can already do what you want like this: > > SELECT * > FROM A FULL OUTER JOIN B ON (x=y) > WHERE x IS NULL > OR y IS NULL > > So for example: > > postgres=# select * from a; > i > --- > 1 > 2 > (2 rows) > > postgres=# select * from b; > i > --- > 2 > 3 > (2 rows) > > postgres=# select * from a full outer join b on (a.i=b.i) where a.i is > null or b.i is null; > i | i > ---+--- > 1 | > | 3 > (2 rows) > > -- > Gregory Stark > EnterpriseDB http://www.enterprisedb.com > > ---------------------------(end of broadcast)--------------------------- > TIP 6: explain analyze is your friend > > -- View this message in context: http://www.nabble.com/Performing-antijoin-in-postgres-tf4358905.html#a12425655 Sent from the PostgreSQL - hackers mailing list archive at Nabble.com. ---------------------------(end of broadcast)--------------------------- TIP 7: You can help support the PostgreSQL project by donating at http://www.postgresql.org/about/donate
